General LSX Automobile Discussion - miss fire questions

i got 99 t/a full bolt on's i hit the car with spray not too long ago, and now im getting p0300 miss fire code. car misses at idle and part throttle cruising i get on the gas a lil and it goes away.

looked at spark plugs and they look ok, changed the wires don't know what else to look at they say weak fuel pump can cause this or fuel regulator ? what about fuel filter ? i doubt its a coil or injector cus the miss is all over the place looked at live data and i got all 8 missing. if it would be a coil or injector it would be one 1 or 2 right ?

need some help car sounds like shit and its chugging gas like never before.

thanks in advanced

Im on the mobile site so I cant see your sig. Does the car still have cats? If it does one of them could be clogged. Is the nitrous dry/wet and how big of a shot are you spraying. What plugs are you using? I'm just gonna guess and say your 02 sensors are screwed up. I've heard and experienced that N2O tends to wear them out pretty quick especially if your tune is on the rich side of things.

Im on the mobile site so I cant see your sig. Does the car still have cats? If it does one of them could be clogged. Is the nitrous dry/wet and how big of a shot are you spraying. What plugs are you using? I'm just gonna guess and say your 02 sensors are screwed up. I've heard and experienced that N2O tends to wear them out pretty quick especially if your tune is on the rich side of things.

long tube headers no cats im hitting the car 100 shot wet. im running ngk 6 heat range i have no tune at all and ran the car with race gas for a lil safety. im thinking the race gas could have messed up the o2 sensors but the car dose not do it all the time. it comes and gose while driving.

Lead in race gas will kill your o2's in a hurry. I suggest you change the o2's, get a tune for nitrous, and never run leaded gas again unless you go speed density and have a tune for race gas.

And quit spraying it without a tune...

Lead in race gas will kill your o2's in a hurry. I suggest you change the o2's, get a tune for nitrous, and never run leaded gas again unless you go speed density and have a tune for race gas.

thanks so that's most probably whats going on then. i was a lil worried cuz to tell u the truth i was trying to blow the motor that night. cuz of my uncle told me if i blew it he was getting me a 6.0. i ran it with the predator tuner with timing advanced and leaned out and no boom. i did have a richer fuel side im going to try on my brothers o2s and see if it gets better thanks for the help.

Wait...if your trying to scatter it...your on the right track...:confused:

Wait...if your trying to scatter it...your on the right track...:confused:

naw that night cuz i didnt want to spray and he told me it was going to be fine and he told me that if i blew it he'll get me a 6.0 so i went for it but it held up fine lol

Bww is right on the money. If I was you I'd get a tune for the spray. And go with NGK BR7EF plugs the TR6 is NOT a nitrous plug

the tr6s are the one's i seen everyone run on 100 shot. they say the br7s are for 150 range correct me if im wrong. im looking to go 175 200 when i tune

i also went with a th350 tranny brake and i haven't tuned for it either so i don't know whats triggering that misfire

im not trying to blow the motor. i was that night but i need to keep it running for a lil while.

ok guys i swapped out the o2s and the o2 codes went away. the car it driving normal at part throttle but still feel a little miss at idle. cables are new plugs look ok abut 3500 miles on the plugs. what else do u guy think i should look at?
thanks for the help so far

Unhook the negative battery cable for a little bit and see if that helps. Might try a crank relearn as well.

Unhook the negative battery cable for a little bit and see if that helps. Might try a crank relearn as well.

ok i erased the codes with the diablo tunner i should still disconnect the batt?
i dont know how to do the crank relearn?

ok i erased the codes with the diablo tunner i should still disconnect the batt?
i dont know how to do the crank relearn?

crank relearn you will have to do with a Tech II or equivalent. basically all it amounts to is syncing the cam and crank sensors to account for timing chain stretch...or other variances in the valve train.

ok thanks i gotta look for some one with one then i left the ground off for about 6 hours and nothing the miss on idle is still there minor but there