My rx8 has recently been idling rough and I thought it was a vacuum leak but now I'm not so sure. I have replaced my o2 sensor, my MAF sensor, plugs, coils, and I've done a smoke test on the intake and it didn't appear to have any leaks. My long term fuel trim is around 22% and my short term is all over the place. I've tested compression and all rotor faces were in the mid 90s within 3-5 psi of eachother so I don't think that's the issue either. I will attach a graph of my short term fuel trims at idle. any help would be appreciated.


Edit: on second thought this graph looks like a pretty consistent pattern. I still know my long term fuel trim shouldn't be 22%.

 

What’s your MAF rate at idle after warm up with all the accessories off?