Derf00

yeah, this was what I was thinking. I thought SCT canned tunes were only good for tune + CAI...?

I'd contact a good local tuner and just have the thing dynoed. Let them sort it out and give your car the power it deserve with those mods.

99gt302

The thing is , I drove the car with the sct tune and cams for 4 months with no backfiring or spark knock without a tune, so before I put it on a dyno and blow it up, I would like to fix the above issue.

hootie_john

What have you checked? Any of the suggestions mentioned earlier in the thread? Air leaks on the intake side will cause mad problems. Fuel filter? Fuel pump? Fuel pressure? Plugs? Coils?

99gt302

New plugs, I did a smoke test, no leaks from anywhere. Fuel filter is new. Fuel pressure was around 40 @ idle.

I got a few o2 codes yesterday after driving in a heavy rain, I do have home made extenders on them for the headers. Can I unplug those and see how it does in open loop putting around to rule out o2?

hootie_john

That would be a good place to check - funkiness from the O2s would cause issues I would think.

99gt302

Will I be alright to drive it without the front o2s plugged in and let it run off the stock table... my tune is the SCT 93 performance tune with jlt 110mm

decipha

popping through the intake is a lean condition

get yourself a data logger and check to see what the hegos are doing and how much fuel correction is getting applied

your best bet for DIY tuning support is http://www.efidynotuning.com/forum

99gt302

would the o2 sensors cause the lean condition?

99gt302

Also forgot to mention that when the car is in open loop , it idles like a dream.... then when it switched to closed it started idling rough again.