poor acceleration, no power on 1997 GMC Yukon

97 Yukon has poor acceleration above 20 MPH. Sometimes problem goes away for a few days. Just replaced fuel filter, Had fuel pressure checked and is is 62 PSI. Had MAF sensor and injectors replaced a few months ago. Please help.

Asked by for the 1997 GMC Yukon
1 answer 2 comments
Is the "check enigne" or "service engine soon" light is on? A fault code would help but they do not "diagnose" problems- they just give us an area to focus on. Good luck, Greg
No. Unfortunately, no error codes at all after MAF sensor and an O2 sensor replaced. I was looking at the other problems in this category and now wonder about the EGR valve. What are the symptons if this has failed?
The egr valve will only cause a rough idle or stalling at idle. Have a muffler shop test for a plugged catalytic converter. Greg