My car has both of these codes. I have replaced the coilpacks, the spark plugs are new, a new set of ngk wiresets are coming on Thursday. I fixed the spark plug chamber not threading in properly so that's now fine and dandy. I cleaned the MAF sensor and wiped down the eccentric shaft position sensor, as well as stomped the brake pedal 20 times till the oil gauge sweeped.

I have no idea what it may be. I will have my mechanic come out and do a compression test (although he doesn't have a "special rotory compression tester") and I contact racingbeat awhile back asking them if a normal compression test would work fine and they replied with yes.

If it turns out the engine has low compression and its time for a rebuild, should I skip the hassle, and sell the car for pennies practically, or invest in it? I love the rx8, its my favorite car but I don't want a money pit. My car was first sold mid 2007, so would it be possible that I may still have warranty on it? I would assume the warranty ends 8 years from the date it was first sold correct?

I searched the forum, and did most of the fixes that are suggested. I should add, i have a midpipe from agency power as well. and I checked the coils and cables using this method.
https://www.rx8club.com/series-i-do-...-wires-222641/

and received a constant spark.

 

You need to address the p0171 code, as well.

Have you read the misfire sticky? It's found at the top of the troubleshooting subforum. Follow the steps and report back.

As far as should you sell if below compression: only you can decide that. It depends on your wallet, patience and love of the car.

Do some further reading.

 

Sadly i wouldn't know where to start with the p0171 code short of doing a full vacuum test.

Also I followed the misfire sticky. I did just about everything short of replacing the MAF sensor completely. Replacing fuel pump. Or test it. I would need to do that.

So when mechanic comes to do a compression test, it will reveal if the engine is fried. I just hate that the thought of that happening is a possibility. I mean, I took care of maintanance and I could be out thousands. the car is salvage so selling it may not even get me 2k for it.

 

Check the vac lines on the intake accordion. Make sure there are no cracks in the rubber or anywhere else. Smoke tests are a viable option for checking.

And you may get an idea of compression from your mechanics tool, but you won't get a proper reading. If you don't want to put in for that, then you won't want to put in for a rebuild. My advice is to sell the car as is.