GM Repair Problems? Ask GM Repair Expert Now.
My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.
I have seen a restricted catalytic converter cause all of these codes here and the no power issue.If an exhaust back pressure test was not done I would have this done to see if this is an issue with a restricted exhaust with the catalytic converter needing replaced.
If this is tested and found o.k. then I would have the intake checked for any vacuum leaks as this can cause this issue as well.
Exhaust back pressure should not exceed 1.5 psi at any rpm range.
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