When I was getting my car tuned today, Chris at Speed Demon was really surprised I had no misfire codes from the cam. So I unplugged the MAF, IAT, and the 02's and still no code. The SES light comes on when you start the car, so I am sure it's not a burnt out bulb. Any ideas? Help would be greatly appreciated. I'm thinking it might be a bad PCM.

Thanks
Ryan

 

Hoping it would throw a misfire code, I unplugged a coil pack. Still no SES light. Then I attempted to pull the codes thinking the cluster was bad and the light was on, just not on the cluster.

It had a pending code, but no trouble code. The code was P153 i believe, coil pack malfunction or something similar. But still no trouble code??????????? Anyone?

 

Anyone?

 

p0153 is a o2 function (heater element iirc) i get them now and then after headers on an old o2.

anyhoo most tuners disable the misfire detection (32767) so the SES doesn't flash at rpm's where misfires are going to happen. If you misfire and the p0300 is disabled the SES will flash usually at idle then stay off since the code is disabled, a tuner will then tweak out the misfire sensitivity so this light doesn't flash and you don't get angry.

but the fact is most cams of decent size misfire like mad, thats what loping it, its a misfire and prob not good for the oil/motor since its leaving alot of non-complete burn to pollute your oil. thats just my opinion though.

ask the tuner if they desensitized misfires and disabled p0300

 

He didn't disable the misfire codes before I installed the cam. That's the thing, I went to get a full tune and had no misfire codes like I should have. Then I unplugged a coil and still had no trouble codes, just the pending code about the coil malfunction.

And it wasn't P153, that's the old code I was getting a few months ago. Sorry.