98 Tahoe bad miss.

[smyrna13]

Okay, here we go, I've tried several forums on the net and to no avail. I bought my tahoe a few months back and since i've had it, its had a bad miss while going down the road, but at idle or WOT its perfectly fine. here's a little info on the truck, its a 98 2 door tahoe 4x4 the motor and trans were replaced 2 years ago. The previous owner replaced the fuel system from the pump all the way to the injectors, did plugs and wires, distributor cap, filter and all that and it still did this. It has Edelbrock headers on it, and true duals with no cats. I've had some ppl tell me its because of the rear o2 throwin a code, and other ppl telling me its got to be something else, because the post cat o2 doesnt effect performance. Anyone have any experience on this? the codes say random cylinder mis fire, cat converter not functioning, and something about the rear o2.

 

[TIM Z]

random Cylinder misfire usually means a bad injector.

Have you changed your fuel filter lately?? They are very important to keep changed.

Post the code your getting,

My Dads 99 burban had cylider misfire, it was a bad fuel injector, it would miss and run like it was bieng held back..

Put in new injector and ran awesome.

 

[smyrna13]

Yeah, the previous owner had a shop do the injectors, and their reputation isnt that great, maybe they did a mess up with the injectors. I'll get the codes run again tomorrow and i'll post them, I'll prolly do the filter tomorrow too, i was told it was new, but ya never know

 

[kjlegend]

The injector system is a spider injection system. I just replaced mine due to the exact same symptoms as yours and it runs perfect now. I'd replace that and it should do the trick.

Also make sure the fuel filter is new, easy, cheap insurance.

 

[smyrna13]

Wasn't able to get the codes run today, my battery was dead and the check engine light wasn't on when it got jumped off. But I would like to add, after I turn the truck off I hear a sound, it sounds like the fuel pump still pumping, but its coming from under my hood, I've been noticing it but never paid attention to where it came from until today. Could this be a possible symptom too? it just started in this past month when it's run the worst. And after checking again it sounds kind of like air rushing somewhere.

 

[smyrna13]

ok, i feel like a D.A. but all it was was the timing was a tad off. its fixed now, and runs better than ever