Srt4...

iTrader: (7)

I'm having a backfire problem in 3rd and 4th gear while full boosting only when i hit 4000rpms each time i wot. My mods are in my signature and I'm boosting 28psi. I havnt had this problem ever. My car is detuned at the moment since the meth has been disconnected. Could this be a possible boost leak or spark plug problem. Any help or suggestions would be greatly appreciated.

chaotichoax

iTrader: (149)

change the plugs and see if it goes away...if your tune isn't up to par with the mods/fueling you are running you are going to be all out of whack

chaotichoax

iTrader: (149)

change the plugs and see if it goes away...if your tune isn't up to par with the mods/fueling you are running you are going to be all out of whack

evo8nfs

iTrader: (2)

I agree With That guy ^^^^^^

Srt4...

iTrader: (7)

So i have changed the spark plugs. Car runs better but still has backfire with hesitation at wOT at around 4000rpms. What else could i check

dxbtune

check your FPR , make sure your set to 43PSI with your finger on the vacuume after disconnecting it from the fpr...

heel2toe

iTrader: (41)

possibly a boost leak? Do you have a wideband? Either that or you car just needs to be redialed in.

TIBOevo

iTrader: (8)

i would close the spark gap alittle more. i would also recomend a ignition amp too.

LV///R

iTrader: (36)

How many miles on your 03?

Have you changed your plug wires? I had a similar situation, and forgot to change my plug wires at 60,000 miles. Once I changed them, problem went away.

Other than that, when you changed your plugs, did you regap them to a lower gap? This is important especially if you are running high boost.

AWD_Terror

iTrader: (6)

lower gap and checking for arcing on the plug wires will likely show you your problem

D420mac

iTrader: (1)

No one thinks he could just be running rich?

AWD_Terror

iTrader: (6)

doubt he is that rich to cause that.

Srt4...

iTrader: (7)

I jst hit 80,000 miles. I have not swaped out my wires yet that was going to be my second guess. When I put my new plugs evo8 9's i gapped them at .028 which was recommened here for high boost high horsepower evo's. I turned down the boost from 27 to 24 psi... I'll try the new wires and check my fpr. Question could I have a cut in my fuel map cause of a mishap on a tune since my car was originally running meth and no longer is now without a new tune? This problem occurs on wot at 4000rpms each time

Srt4...

iTrader: (7)

Thx again for all responses and suggestions

dxbtune

Mine was randomly doing the same thing until i re-adjusted my FPR, it was way too high for some reason out of the blue...