I have a tuned 05 manual rev up coupe - A/F ratio is going to 18 when taking foot off the gas even at higher Rpms - exhaust screams at me. It is not constant, but today it has done it almost the whole time I was out cruising around. Normal A/F is 12 ish. Exhaust does not scream when it is at the normal A/F it’s more of a rumble sounds nice.
I have a P0455 code ( evap emission system leak detected - large leak)
I have code P0037 H02S heater control circuit low (this code started after changing the primary bank 1 sensor 1 02 sensor in the header also changed header - before changing this sensor did notice the wiring harness for the secondary o2 sensor was looking a little rough but since I don’t have cats and tuned didn’t think this o2 sensor mattered?)
code P1706 not sure what this is heard it’s neutral safety switch but my car is manual so idk what that code is about.

any Info on this issue would be appreciated just put the CEL codes I have incase any of them match up with the problem.

cleaned my maf sensor the other day and it did not resolve the issue. Have also cleaned throttle body. And fresh cai filter.


thanksss!

 

A/F going full lean is normal when you let off the gas since the car basically goes into fuel cut. A/F under load is what really matters.

For the codes you're getting, download a copy of the FSM and troubleshoot as needed.

 

hey I appreciate your reply! I understand what you mean but for my car it is not normal - idk if it’s bc it’s tuned.. not sure. But when the exhaust changes to that tone - not normal for my car. And when it does that tone I look at the a/f ratio and it’s at 18. When it’s running normally and not doing this and I’m decelerating - the exhaust does not sound like that it’s more of a rumble and some pops ect and the a/f doesn’t go to 18 not even close. This is why it’s so frustrating bc anyone I mention it to says it’s normal but I know my car and how it’s supposed to sound and that ain’t it 😂
🤯