I have burned up 3 cats since December. I hav changed all the o2, map and maf sensors. Plus when on a cold start the car the rpm rev to 2000 the creeps back and when i take off it boggs out until i release the gas and step back on the pedal. Also when I put the car in park the engine revs up n dwn from 1200-2000 rpms. I have a aem v2 cold air intake. any suggestions on what it could b???

 

Are you getting any CEL codes? What type of CAT are you using (I assume its not OEM)?

 

No error codes. And it's an aftermarket cat from the muffler shop by the house. I been going there for yrs. u can smell soooo much gas coming from the exhaust

 

Are you sure? You should probably be getting multiple codes either as misfire, o2 codes, cat code (p0420, etc.). You really should be using an OEM Cat. However, if I was diagnosing this I would be looking at live data; o2 sensors, short term fuel trim, long term fuel trim, etc. Hopefully someone with a bit more experience can chime in but I dont know how much we can figure out with codes or graphs of live data.

 

It's hard trying diagnose this with no codes. I have nvr had codes for my o2 or cat during this whole process. All the codes I had I fix which were unrelated to this problem.