Lt4 Throwing some Codes...
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From: Dallas TX
Another LT4 Throwing Codes....
I know there is a similar post going right now....but, I didn't want to steal his thread, and I think mine may be slightly different. Alright...I have a 96 lt4 w/hotcam...engine rebuilt 20K miles ago. I bought it 10K miles ago. It has had a misfire code randomly occuring since I bought it. Also the SES light has come on and off since I've had the car. The previous owner said something about the rebuild / overhaul causing it to throw a fuel mixture code occasionally which was why the light came on and off. I dismissed it because of that. Stupid I know. Anyway...enough history...
I went to the ONLY autoparts store in my tiny west texas town and tried to pull codes. Unfortunately the code puller died before I could write the codes down...so here are the 5 codes as best I remember them.
Auxillary input/output
O2 Sensor High Voltage Bank 2 Sensor 1
Misfire
Catalyst below efficiency.. ( Might be a little paraphreased )
Engine Lean
I have read some of the other posts and at times have noticed a black soot all over the rear of my car. I haven't noticed it recently, however, my SES light is on all the time now. Let me know what you guys think...
I went to the ONLY autoparts store in my tiny west texas town and tried to pull codes. Unfortunately the code puller died before I could write the codes down...so here are the 5 codes as best I remember them.
Auxillary input/output
O2 Sensor High Voltage Bank 2 Sensor 1
Misfire
Catalyst below efficiency.. ( Might be a little paraphreased )
Engine Lean
I have read some of the other posts and at times have noticed a black soot all over the rear of my car. I haven't noticed it recently, however, my SES light is on all the time now. Let me know what you guys think...
Last edited by McGaffin; Jun 29, 2005 at 09:04 PM.
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I'd bet even money you're still on the stock tune. The hotcam will cause it to throw misfire codes on a stock tune and make it do some other funky stuff like what you are describing. I really think its all related to the hotcam. If it bothers you then have acustom tune done on it or send your PCM to www.pcmforless.com and for about $200 it should cure all your issues. My LT4 has the hotcam and a stock tune and it does the exact same thing you are describig. I just havent gotten around to getting a tune yet.
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From: Dallas TX
I forgot to mention one thing. The previous owner also installed a hypertech power programmer to the car. Does this change your diagnosis at all? I have the programming module but don't have a clue what to do with it. From what I have read, there is no real benefit to having it except that you can change rear end gears, tire size, rev limiter,etc...
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From: Dallas TX
I am thinking of taking my car in to Corvette Garage which is just down the street from where I live and letting them program the chip. However, I am sure that it will end up costing me more that way. The other option would be to use that pcmforless site, but I am hesitant to off and do that without knowing whether or not having a hypertech power programmer installed changes this previous diagnosis. What sucks, is that I have to get the car inspected by.......today. Oh well....I am not too worried about that right now. Also, should I expect to see an increase in power? I saw the dyno sheet for this car when I bought it and it was showing 350 RWHP.
