Bumi

2004 RX-8 Automatic sports/touring 1.3
I bought this beauty 2 and a half weeks ago. Great car I love it so much if this car had a vagina I would have already cheated on my girlfriend in an instant thats how much I love it. A few days ago my check engine light came on I was really surprised because the car just hit 74k miles. The car was driven mostly in North Carolina and now in Virginia. Ive done some of my reading and know the basics about my car but im having some major trouble right now. On my carfax report at 65k miles the exhaust system was fixed and when I asked what that meant to the dealer he said the catalytic converter was replaced. To my surprise when i took it to O rileys to scan the engine light it got a 420 reading. Something about emissions and me not having a green footprint in the environment. The day after that I took it to the only mazda dealership in the area, duncan mazda, which is mazda ford lincon and another car company combined to make one big dealer. I got a compression test first there and it said that it was a bit low but still in the range, this is my first worry because ive read if the compression is low you are "fucked" and need a new engine. This is on the paper I have no idea what it means. "BOTH BANKS ON LOW SIDE BUT WITHIN SPECIFICATION. BANK 2 LOWER THAN BANK 1. 814 745 737 KPA, 107 97 96 at 243 rpm, 683 721 691 KPA, 90 95 91 PSI AT 247 RPM. Any way to higher the compression or no? My second worry the most important is this ******* guy at mazda said my catalytic needs to be switched "the outside looks like new but the inside is damaged, MAZDA part on backorder 2-3 months 1800$ for the piece, but I found aftermarket catalytics and with labor and everything I can quote you for 1300$." NOW I KNOW FOR A FACT CATALYTIC CONVERTERS DONT DIE IN 8000 MILES....... After telling him that it was switched and what could be the reason why its bad again and the guy literally said "Couldnt tell ya bud, wasn't the one who put it on." I cannot pay 1300 literally a college student they dont want to finance me either. My boy Houston TX, with the same exact year and color said I could take out the catalytic and buy a BHR mid pipe and install it my self and when inspection time comes around I gotta put it back on, his mileage is at 110k. Now ive never worked with a car like that Ive changed the battery, i know pretty cool, so i am kind of scared i dont want to **** up my car more even though he said he did it himself and he can help me put it on through facetime.
I drive it pretty normal going around 80 on highways 100 to pass trucks, I never let it beep for more than a second if i redline I try to redline 2 3 times a day and I always sit in the car for a few minutes before driving. I started putting 93 octane into my tank ever since I got it and I used redline additive 2 fillups ago. I called a rotary engine mechanic 3 hours from me and he said they stopped working on rx-8s 6 years ago and that I should look into selling my car now , not what i want to hear at all.
EXTRA: mechanic at mazda said who ever had this car before me took care of it VERY well autochecker rated it a 67 out of 100 while the average was 39 to 56 maintenance wise. I live in a small college city in the mountains where it snows but not that much. I put semi synthetic 5w-20 oil but im thinking of using 5w-30 next time because of the weather. Also any known good rotary mechanics near blacksburg north carolina west virgina or dc area.

200.mph

iTrader: (9)

your comp #s arent bad however an 04 auto rx8 is the worse 8 you can buy. its a 4port/4spd. when was the last time the ignition was replaced (plugs, wires, coils)? if they are bad it will cause misfires that will clog a cat and ruin your engine. any flashing cel at higher rpms? decatting a rotary imo is a very smart move but will give you a constant cel and some people dont like the smell

Loki

iTrader: (1)

Potentially the cat was replaced, but the original cause of the first cat dying was not. So it killed the new cat too. Do you know if ignition coils were ever replaced? Bad coils kill cats, bad cats kill engines.

​​​​​​Do not put an aftermarket cat, it will die in no time. Speaking of which, is that what the previous owner did? Because that would explain it. You need an original cat if you're going to have one.

If they told you the cat is physically broken up inside, I would definitely stop redlinining, and ideally stop driving altogether until it's fixed. Doing so risks your engine.

May want to have a read at rx8help.com, there's a nice summary of things to know. There aren't many, but this is one.

​​​​​​

Bumi

200MPH It was the only coup/sports car in the area under 8000 and under 80k miles probably my best choice really didnt want a 2011 toyota corolla. On my carfax report it doest tell me if they were changed all it says is it passed inspection. As i mentioned I went to the mazda dealer the guy their tied everything to my cat... even that noise would go away if i got a new cat. No CEL at high rpms ever CEL only happened after i scraped the bottom on a pretty high bumper going probably 1 or 2 mph turned my car off to go to the mall 4 hours later turned it on with a CEL, there is a wire down there probably my o2 sensor idk if its damaged. I know of the constant CEL i dont care I would rather look at a fake CEL than a real one LOL. idgaf abt smell ive been congested for weeks i cant smell anyways. would you say buying OEM ignition coils are better or an after market one such as BHR or another company?

Bumi

Loki, the mechanic said the cat was the ONLY problem. I dont have any loss of power doesnt feel sluggish then again i did only have the car for 3 weeks. Dont think ignition coils were replaced I asked if they checked the spark plugs and they said the rotary mechanic probably did if there was a problem we would tell you. Honestly feel like they are lying just to make money. I think the previous owner did put a aftermarket cat because it was replaced. No he said the outside looks new inside has some damage I can keep driving it but of course the best option is to get it changed. Did not say physically broken up inside.

200.mph

iTrader: (9)

i always suggest a decat and bhr ignition is a great choice. wait a sec, you paid 8k for an 04 auto 8????????

Loki

iTrader: (1)

The P0420 code you got is not lying.

That should probably be the last time you see this mechanic. I assume he's not familiar with RX8s or rotaries? "Probably looked at" is not helpful, neither is "its damaged, but its ok to keep driving". Can you take a picture of the cat from the outside at least?

What is the noise you have that he says should go away?

The wire you saw, are you saying it's dangling and not connected to anything? I mean that would cause the P0420, but also a pretty obvious fix the second anyone looked at it?

Bumi

yea i am thinking of just buying a midpipe and taking the cat out because no way i can pay 1300 upfront. I know its illegal to decat but how illegal and is it noticeable enough for a cop to pull me over and give me a huge fine. Yes around 7300 it was 9100 then i brought it down. If i cannot find bhr ignition coils what should i buy. I also saw packs of ignition coils (4 pack) whats better just getting a singular or 4.

200.mph

iTrader: (9)

no offense but you wayyyyyyy overpaid. when replacing coils i always did all 4 with wires and plugs. decat isnt bad and with the oem mufflers it shouldnt attract too much attention. i ran a full exhaust with no cat and never had any issues

Bumi

Well it was like i said the only sports car under 80k miles. "i ran full exhaust with no cat" could you elaborate what you mean by full exhaust? And with an aftermarket midpipe would I be able to transfer the OEM mufflers onto it? By bolts or welding? Thanks for your help by the way.

200.mph

iTrader: (9)

shouldnt say full exhaust rather a manifold back system which replaces the cat and oem mufflers

Bumi

its connected i just checked i took some pictures of the cat and by the wire. The noise is the video i included in my first post its a .mov. The mechanic was giving me very open ended responses just not caring probably trying to make money off a kid. I also have a bit rough idle my friend did say he saw blue smoke when i sped off.

This is the cat i think lol




This is close to the wire looks pretty bad is this the cat?

Wire

Loki

iTrader: (1)

The first 3 images are your muffler.
The last 6 are the cat, looks like everything is plugged in. And it looooks like it's a stock Mazda one? It's missing all of the heat shielding but it looks about right. All the same, 0 internal damage is acceptable.

The little squeaking noise has nothing to do with the cat. I'm not sure what it is but its not that. Does it become more frequent with engine speed? Does it only happen at idle?

200.mph

iTrader: (9)

loki is correct, the first pics are the muffler. as for the cat im not sure if its oem, it looks like its welded in and i cant see if the factory bolt in flanges are there cause the pics of the cat are a little too close. it has been a while since i messed with a factory cat tho

Loki

iTrader: (1)

Yeah the welds look a little suspicious to me, but the heat shield studs around the sensor hole I thought were a clue. Didn't think aftermarket ones would come with those.

You might be right 200, the stock cat isn't smooth like that, it has a bit of an indent in the middle where the sensor is too. Maybe they welded in a stock cat for a different car? A Mazda 3 or something?

200.mph

iTrader: (9)

idk hard to tell from the pics bit it seems off to me to be an oem 8 cat

Loki

iTrader: (1)

Actually I guess it's easier than that: the stock cat isn't a weldable part, it comes with all of the heatshielding and such, so the fact that that is all missing means it's probably not a Mazda cat and needs to come out.

spectre6000

Before you go rolling dirty, know that it's totally possible and not at all unreasonable to keep it clean and legal. Search around on here for inexpensive cat options. Call around to a bunch of muffler shops near you, and you should be able to find someone to weld it in for you for very little money. I once had... sorta the equivalent of a catback system made from scratch with an off the shelf muffler, all done and out the door in the vehicle for $250. I say sorta because it was a pre-emissions car, and they obviously don't have cats, but was about the same amount of exhaust system.

Before you do, use what time you have before you need to pass an emissions test, and fix what killed it. Whenever I get a new-to-me car, I "baseline" it. For some cars (50s vintage, early-60s), that's wiring harness, whole new brake system, etc. For something new like this, basic consumables. Fluids. Check your rubber parts (it's a little soon probably, but better to check). Anything that tends to go bad. BMWs like to eat cooling systems for instance, so new radiator, belts, water pump. In this case, you're eating cats, so something is either chewing it up or fouling it. Since your compression is good, look at fouling first. That's the ignition system recommendation. Coils, wires, plugs. Another contributing factor could be oil consumption, which means slightly different things with a rotary, but oil consumption beyond the norm would put you in the direction of a rebuild anyway.

Hypothetically, say you do decide that a rebuild is necessary. Don't freak out! Rotaries are ridiculously simple. Three moving parts and all that. High school kids rebuild rotaries on their parents' garage floors all the time. No special tools required. Worst case scenario, you can be a remanufactured engine from Mazda for $4,500 or less. Cheap as far as engines go. Engines on these cars get rebuilt on a much more frequent schedule than piston engines, but they're so easy to do that it's an acceptable compromise.

Also don't sweat the comments about paying too much and whatever. We all start somewhere. You like it, and it's worth it to you, and that's what counts. If the bug keeps biting you, it won't be your first rotary, and you'll make up for it with killer deals on the most desirable cars and parts down the road.

Loki

iTrader: (1)

I don't think some of that is very good advice. Cheap cats are more of a liability than a repair on these cars. And while kids might rebuild rotaries somewhere, how long those rotaries then run is a different story.

Bumi

Yea Loki and 200 mph looking at the pictures it does seem welded on I looked at a few pictures of stock cats and doesn't look close to it. OEM Cats are around 1000 while ive seen some after-market ones such as walker Magnaflow and other random ones off ebay. What would yall recommend overall on how i should go with this car. Please be honest if your going to cuss me out but give me valuable info ill take it :D. No the sound is only on idle and it goes away its not always there.

200.mph

iTrader: (9)

cats on a rotary imo is pants on head tarded. i agree with loki on the rebuild stuff too. its not just the seals that wear out but also housings, irons, rotors, bearings, e shaft. not everyone can tell what parts can be reused so it brings into question the quality of a kid rebuilding a keg on their parents garage floor.

spectre6000

If we're talking GOOD advice, this is a college student who really doesn't need to be spending the time, money, and brain capacity on a high maintenance sports car... Should have bought something inexpensive to own and operate that won't give much trouble for the next (however many) years. That ship has sailed though.

The situation is that the guy/gal bought a four port auto for an amount that doesn't seem to have left much for the high maintenance budget of a cheap used rotary, and doesn't know the difference between a muffler and a catalytic converter (OP, this is not intended as a slight so much as trying to put things in perspective). This person is fresh. Tabula rasa. Telling them to roll dirty is terrible advice that can only deepen the hole. This isn't a track toy. If they get caught by a ticket happy cop (Remember college town cops? 'Cause I sure do.), they could end up needing to come up with all the money in a hurry with someone actually coming behind to check their work and receipts. A cheap cat isn't going to last forever, but if everything else is properly looked after (OP, get reading, you inadvertently signed up for another 3 hour course here), it'll get them through school to a job with a salary where the cost of a cat or another car is not as much of a concern.

And rotaries run just fine with cats, just like diesels run just fine with their emissions systems, just like air cooled engines run just fine with all their fins and tins, just like carbies/fuelies run just fine with their carbs/fuel injection. This isn't a track toy trying to make all the power. It's a college kid's get around car. The gains to be had from going catless aren't in play here.

Good advice: If you can afford it, take it to a rotary shop, have them do a full checkup. They're probably going to replace the ignition (coils, cables, plugs). Then, after that is done or at the same time, replace the cat with an OEM one. You'll be good for a while after that (or until something else goes wrong).

Slightly less good, but still passable advice: If you can't afford that, find yourself a decent but inexpensive cat, replace all the ignition stuff. It's easy cheese, and the FLAPS (Friendly Local Auto Parts Store) counter guys may even be willing to show you how in the parking lot. Then do like I said and call around to find a muffler shop willing to install it for you on the cheap. That'll get you by nearly as well, but you're swapping the shop fees for tools and time. The tools will come in handy, and your time is cheap right now, so that will likely be the preferred balance.

200.mph

iTrader: (9)

i disagree here, along with proper maint. decatting a rotary improves longevity imo. plus i doubt a cop is gonna try crawling under a low car checking for a cat. if the 8 is lowered and or has side skirts theres zero chance of that happening on the side of the road

spectre6000

There are cops who are also car guys. Ever been to a Cars and Coffee? They're all over the place, and not always in uniform. Some are sympathetic, some aren't, and some of those sympathetic cops can have a bad day sometimes or get rubbed the wrong way. Reminder in case it's been forgotten: OP is a college kid in a college town (a small college town at that) with small college town cops. These aren't cops with bigger fish to fry, and college kids probably annoy the **** out of them. You don't have to go crawling around on the ground to tell when a car is catless, anyone who knows anything about cars can smell the difference between cat and catless (as has already been mentioned) from behind the wheel at speed going the other way.

As for decatting being about longevity, I call more BS. I know it's popular BS, but still BS. Cats don't kill rotaries. Poor maintenance kills things that kill cats, and dead cats kill engines of any sort. Removing the cat just make it easier to neglect proper maintenance, and get away with it until something even worse happens. What does kill rotaries (Renesis anyway) is carbon build up. What causes carbon build up? Poor ignition/partially burnt fuel. What happens before carbon buildup takes out a rotor housing? It clogs a cat. A cat is cheaper than a new engine. Think of it as an early warning system if you need to. Either preventing a rebuild, or saving rotors and housings so that the rebuild is cheaper. Decatting in this situation would have allowed the failing ignition to continue failing for a little longer, then it could be much more catastrophic. It's not aiding longevity, it's making the situation worse a little later.

There are situations where going catless makes sense (they're called track-only cars). This isn't one of them.

Bumi

There are alot of cops but there are alot of moddable cars, saw a kid with a focus and a turbo also hear people revving their **** 24/7. You are right taking out the cat is just a temporary fix i want to find what created that in the first place. The small whistling noise comes from inside the intake, , tittle doesnt fit the video tbh. I went for a drive and decided to push down the gas a bit. Heard a whistling noise just like a turbo, but i dont have a turbo :/. I dont think the ignition coils or spark plugs have been changed I have jumpy acceleration when i switch gears at high rpms and the exhaust sounds a bit less loud so it may have some carbon buildup. Autoparts store guy said get some CATACLEAN and see how it is, he has miata and had a rx8 before that. I asked him about mechanics he said none in the area. Im willing to drive 4 miles for a good mechanic towards the DC area because I know people up there I can stay with. planning on changing my coils and plugs first driving with the cat for maybe a thousand more miles until I have enough money to get an OEM one or just a regular aftermarket.