ForcFed97

Since I've had my car back from the shop. I can't seem to shake an engine misfire code. I haven't exhausted all my efforts to diagnose the problem, but want to throw the subject out to see what you all say.
My LT-1 as is has a cc305 cam. The problem started after the cam was installed. I attributed the occasional SES light to the cam install. AutoTap will obviously clear the light, but I'd like to cure the problem for good.
There is an EGR code that is also as prominant. I know this is a direct hint into the problem, but the EGR was just replaced 6 months ago and about 600 miles. Before I go ahead and try another EGR, are there any other possible things to look for?

mighty mex

iTrader: (3)

that cam might be a little too big for the pcm. the knock sensor is prob. mistaken the vibrations from the new cam and saying that it is misfiring.
what i have seen done that helps a little is to clean the knock sensor and wrap it around a couple os times with teflon tape then put it back in. be careful though because coolant might come out of the block when you remove it. also try putting the LT4 knock module that helps out quite a bit too. and then take it from there. let us know how everything turned out.

Gangly

exactly as mighty mex said, my guess would be false knock from the cam...did you do 1.6 RR's with the cam?

ForcFed97

Yes, the motor has 1.6 RR's. The only items it doesn't have are internals. The misfire code is a P300 random misfire. AutoTap senses a misfire in every cylinder every split second. I probably need a knock module to help out. It doesn't seem to affect performance. The light is just a bitch. I'm sure the EGR Code P400 is from the cam also. I'm not worried, but thanks all for the advice.

Gangly

you are most assuredly getting false knock if you put those on there and getting misfires in every cylinder....install the knock module and see what happens, they are cheap and easy to install.

97M6Formula

iTrader: (6)

Is this misfire only happening at idle and then all cylinders are fine once you give it gas? If so its definetly the cam because thats what mine does too and I have the xe 224/230 and many others I know but as soon as I bring the rpms up everything is fine

ForcFed97

Well, the LT-4 module is in. The misfire codes still exist. The car does run noticeably smoother. The slight surge between 1500-2000RPM is gone. Overall acceleration is smoother. I'm not going to sweat the code. The car runs fine, it's just an annoyance more than anything.

Gangly

yeah, dont worry about the misfire code. i have them with my cam and i dont worry about it too much myself. i will get it tuned out when i do the LT1 edit done on my car.