99RebelZ28

After I installed my headers, y, and tb I've noticed that the car does not seem to pull like it did before these mods? If I take off easy and shift at a low rpm and then get on the gas slightly it seems like it wants to stall out, like it isn't firing right? It doesn't seem like I have any low end power, it still pulls a little up top but not like it should. I changed out both front o2s with corvette o2s, changed my plugs, and my wires are new as of last year. It also almost sounds like a harley with pipes, when I shift it crackles, when I left off the gas. so what gives? With such basic bolt ons I wouldn't expect it to run like crap without a tune but who knows. I also have a jet performance module stuck in my pcm that the previous owner put in and I don't know if that would be causing the problem or not? Thanks for the future help.

tylerdj

iTrader: (31)

Did you put sims on the rear O2's?

WhosNXT

^^ You will need 02 sims for the rear sensors. Either that or get a tune and cut them off. Also sometimes you can bang a spark plug and crack it during the Lt install but this doesnt sound like your problem. More likely you dont have 02 sims for the rear and you pcm is dumping to much fuel and this is causing the poping between shifts and loss of power.

99RebelZ28

can anyone else verify this? I've heard they don't effect performance?

bore.me

iTrader: (15)

I have the same problem! i don't have working O2 sensors and it runs crappy at low rpm. Don't O2 sensors increase gas milage and help get an optimum air/fuel ratio? I don't know whether to pay to get new sensors put in or to just have them tuned out.

Frost

iTrader: (45)

this thread is OLD...

You NEED good front O2 sensors. You can tune the back ones out, but the front are for closed loop control. They literally are responsible for ALL fueling outside of first-startup and WOT.