My 1990 Suburban inconsistantly dogs during accelaration and the engine revs while holding speeds around 45 mph. The problem only seems to be present at normal operating temps, not while cold. I have a TB spacer, Air raid intake, and custom dual exhaust with flowmaster 40s, 2.25" pipes, and high flow cats. The timing, O2 sensor, EGR, and PCV are fine. There are no vacuum leaks I can detect. I pulled the tb spacer and intake off and went back to stock, problems persisted. Is it possible there is not enough back pressure in the exhaust system? It threw a code about exhaust being too lean, that is when I changed the O2 sensor. Any help will be greatly appreciated.
Jan 12, 2008 at 5:58 AM