1999 Pontiac Bonneville Engine Problem

This Bonneville suddenly began running erratically. At stop signs it nearly quits. It has left no code. Is there any test for the MAF or TP sensors? Any other suggestions?

I would check all the normal tuneup items. Also check for a intake manifold air leak and bad fuel filter. Cleaning the MAF sensor may help also though I don’t think it would cause an idle problem.

The Check Engine light should come on if there is a problem with a sensor, its probably a fuel problem.

Yep, you should get a code if it is the TPS or IAC. You can put an ohm meter on the TPS and see if you get a smooth response throughout its travel. I would check fuel pressure and fuel pressure regulator and check for any vacume leaks.


smack the maf while ideling.

not stupid hard,did that change its idle?

auto? TCC solenoid?

plug wires?

unhook the maf,did it change ?


graph it,much more accurate.