I have an 04 RX-8 and after 20,000 miles, the CEL light came on. I was told that the reason for the CEL to come on was because I needed to flash my car. Two weeks ago, I had my car sent in to have it serviced for the fuel tank and lower control arm recall. I also had them flash the car to the latest flash. After getting my car back, the CEL was not there anymore, but after 50 miles, the check engine light came back on. Does anyone know what the problem could be. I had an intake and an exhaust on the car when the first CEL came on and even after putting the car back the stock, the CEL is still on.

 

it could be anything, including a completely different issue than before

 

Flashes don't necessarily clear CELs as the issue (failed sensor or actuator) causing the CEL is still present.

F

 

Did you get gas just prior to the CEL illuminating? If so, your gas cap may not be sealing. Check it. If it's not tight, screw it down a couple of clicks and be on your way. The CEL will self-cancel after a bunch of on/off drive cycles.

If that's not the problem, you will need to have the error code(s) read and repairs made.

 

How many drive cycles do you think?

I was forced to buy gas in a part of town I am not familiar with and later on that day my CEL came on. I noticed the gas must have been pretty awful because I started to get some knocking from my engine shortly after I got the gas. I checked my cap and then later went to my normal gas station and filled her up with 93octane and the light is still on. I have an appointment with the dealer on Saturday to check it out. Over the phone they think it could be the CAT since I had a prior issue with my coils which they recently replaced.

 

The gas-cap related CEL will not light for bad gas, only if it is not sealing. As I said, if a non-sealing gas cap was the cause of the CEL and you tightened the cap so that it now seals, the CEL will eventually self-cancel. I don't recall the exact number of drive cycles before it cancels, but I believe it is a double-digit number.

Of course, if you had real engine knock, that could be the cause of the CEL. In any case, if the CEL doesn't self-clear by Saturday the dealer can pull the DTC code(s) to verify the cause, fix the problem and clear the CEL. Let us know what they find.

 

When I got my car back from the dealership after the flash, I didn't get gas and the light still came on. I really need to take my car back to the dealership and have them find out what the problem is, but its just so hard since I go to school and cannot find time to do it. Hopefully the problem isnt that bad.

 

velocityredRX-8: You can see if one of the mainstream auto parts stores like AutoZone or Advance Auto have a CANbus-compatible OBDII reader. If so, they should be able to at least pull the codes and give you an idea of what the problem is so that you can decide whether or not to take it to a dealer.

BTW, the dealer should provide a loaner car if you make arrangements in advance.

 

I don't know if this will help, but I am an '04 owner here with a problem just like yours a couple of months ago. You might want to ask them what code the CEL is giving them the next time you go in. I had to have my fuel evap system replaced (I am not sure what this is, but my service advisor also owns an 8 and said that it has been a problem with some of the '04s) and it took multiple trips (I think it was 5 or 6) to two different dealerships to figure it out. The first dealership just kept reflashing my car and clearing the code. They never even tried to figure out what was wrong. The second dealership cleared it once, then actually checked it out and fixed it the second time in.

 

Im gonna go ahead and take my car in to an autozone nearby and have them figure it out. I'll let you guys know what the problem is.

 

Autozones in California do not check your DTC code for you. It is against the law.
You can loan a OBDII scan tool free of charge (refundable deposit) however, but the tool that they had at my local Autozone was not CAN capable.

I ended up buying one from Kragen for $69. Works great.

http://www.partsamerica.com/productd...artnumber=3030

I have the same problem in my 05'. It keeps throwing P0456 and P0455 DTC codes.

I am hoping that this is just a bad gas cap. Will be bringing it to the dealer to have it checked out this week.

By the way, does any one know if P0456 or P0455 can be related to the intake. Or should I have damaged parts of the EVAP system when installing my K&N drop-in filter.

 

I checked the possible causes for those codes and I didn't see anything that was obviously intake related. Probably just a faulty gas cap.

 

Thanks, that's what I was thinking too. The reason I asked is because the only mods that I've made were a K&N panel filter and a Tanabe exhaust.

 

You didn't mention the aftermarket exhaust. I suppose you could have damaged an evap system component when installing that. As I recall, one or more of the evap system components are located somewhere around the area of the differential.

Just hope that the dealer doesn't attempt to deny warranty work because of the mods. Some can be real hard asses when any mods have been made to the car. Other's could care less. If you have good relationship with your service manager you shouldn't have a problem.

It's my understanding, however, that legally, the dealer must demonstrate that a particular mod has caused a specific problem in order to void warranty on the affected component or components. Some try to tell owners that they can void the entire warranty on the car for one specific problem mod, but that is not legal according to what I have read on the forum. Apparently there is a federal law covering such things.

 

P0456 was the code that I kept getting before they replaced the fuel evap system.

 

The entire Evap system has at least 10 different parts. Can you give us the part numbers listed on the warranty invoice?

P0456 is almost always a fuel cap as it signifies a "very small leak". A few of these caps have devoped a leak at the rivet that holds the tether to the cap itself.

 

I went ahead and bought an obd2 car reader at a local kragen and the code that came up was P0456, which is what others have had also. I want to take it to the dealership, but the only thing is that I have an aftermarket exhaust. However, I did install the exhaust after the CEL came on. I just never had time to take it to the dealership. Hopefully they do not blame the exhaust for being the problem for this CEL. Anyways, I will take my car in to the dealership sometime this week, and hopefully things go smooth.

 

they wont be able to blame the exhaust for the CEL. take it in.

 

I had the same code. P0456 and P0442 as well. I cleared them but a couple days later I ended up with P0455.

I dropped by the dealer last weekend and they told me the exhaust will not be problem. (I have a Tanabe and K&N panel filter.) Just make sure you don't clear the codes.

I will be bringing my car to the dealer tomorrow to have this formally checked out. Will keep you posted.

 

Keep me updated.

 

Not sure if mine is the same issue but my CEL has come on since this past weekend. There is no noticable engine problems, weird sounds, or loss in performance. I do have oil in my intake though (AEM CAI), but there was oil in my intake when I had it stock. Gonna clean that out. I did use a little 87 octane to get me to an area with cheaper gas. I've been using 89 for a while now with no problems at all. But like I said, the car runs fine but getting CEL. A friend told me it could be a gas cap, but I haven't cycled the engine in the double digits yet. Yeah, definitely keep us updated brtzrx8.

By the way, does anybody know a safe solvent or cleaner for the MAF and a proper procedure for cleaning it. I really DON'T want to damage it.

 

Dropped my car off this morning, and they replaced the EVAP detection pump.

I was glad that I called the dealer in advance to check if they had EVAP parts and fuel caps in stock. It'll be a couple of days before I get my car back though, so I won't be able to verify the effectiveness of the fix. They are replacing my rear windshield for a rattle issue.

Best regards.

Brett

 

Any updates brtzrx8? I had my car serviced today and I just received a call from them saying that they couldn't get a reading from their machine in order to perform anything. Everytime that the try and diagnose my car, their machine would just crash on them. In order for them to perform anything, they need to pull up the code. I guess I have to take my car in to another mazda dealership.

 

dealers are so lame...

 

Lame indeed! Tell them to head down to a local Advance Auto Part store and pick up a CAN-compatible OBDII reader for $70. Sheeeesh!

Yeah, another dealer is definitely called for.