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I have a 1997 Pontiac trans am with the lt1. I have had a problem with it hesitating with tcc locked and pulling a hill where it starts popping and missing. I have no codes. Also if i floor it it does the same thing. If I roll into the throttle and give it WOT gradually it will run pretty good. It started doing this after deleting the EGR, and replacing intake manifold. It’s been like this ever since I did that work over 2 years ago. I’ve replaced the opti, put a new set of intake gaskets on, and still nothing. It back fires really bad when I let off the throttle while holding a gear at say 3000rpm. It has no cats. It is pretty modified but the engine is stock internally. Please help. I will answer any questions. My next step is to start looking at fuel trims. I will drive it to work tomorrow with my scanner and look and see. If memory serves me well the car thinks it’s rich and is leaning it out. I’ve cleaned the MAF and done all the basic things in my opinion.
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Many people mistakenly assume the EGR is just an emissions control. While that may have been true in the 80s, and emissions control is one of its functions, that isn’t all it impacts on engines with computer control. The EGR system allows the engine timing to be advanced much higher than normal. You indicated that the engine internals are stock. Deleting the EGR on a car with the stock cam is risky business. The timing table in the engine computer ends up being too aggressive for an engine without an EGR that used to have one. What results is less oxygen in the exhaust stream causing a rich condition at the O2 sensor so the computer removes fuel to lean the engine out. This can surely cause the driveability issue you mentioned. You might want to either put the EGR back on, or put a cam kit in it to adjust for not having the EGR, or a computer that can take an EGR-delete tune.
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