need help!! car is running so slow and check engine light is flashing, hardly boostin

[CG boostin WRX]

a few days ago my car was running fine and rippin running 21 pounds of boost, then check engine light flashed and stayed on and it was hittin fuel cut or back firing its hardly running 7 psi now... and is slow. i need help. taken it to shops but they dont know what is wrong with it because it has too many mods i guess.. can someone please help, pleaseeeeee. check engine light is flashing the whole time i drive now and if i give it full throttle it will back fire. ive checked most lines, and spark plugs. i did install boost gauge and other gauges the night it stopped working, but the boost is the only one that is fully installed. any suggestions? thank you

[rage-wrx]

More info is needed to provide any adequate help.

Check out ***How to Ask a Technical Question!**

[jd92677]

What is the stored code. That would, at the very least, give you a place to start. Right now there is now way anyone can even attempt to give you a direction.

[mycologist]

I'll take a wild guess at the front o2 sensor.

You definately need to get the CEL code read - usually free at Autozone. Get the actual number for the code - "P0..."

Your ECU put your car in "limp home mode" most likely, because there is a serious issue. It is trying to tell you to quit driving it until it is fixed - you should listen to it.

As much information you can provide about the modifications would help us help you. How was it tuned or how is the boost so high (21). What guages and how were they wired - any chance you disturbed the sensor wires etc.

[CG boostin WRX]

I'll take a wild guess at the front o2 sensor.

You definately need to get the CEL code read - usually free at Autozone. Get the actual number for the code - "P0..."

Your ECU put your car in "limp home mode" most likely, because there is a serious issue. It is trying to tell you to quit driving it until it is fixed - you should listen to it.

As much information you can provide about the modifications would help us help you. How was it tuned or how is the boost so high (21). What guages and how were they wired - any chance you disturbed the sensor wires etc.

i took it to 3 different places.. they couldnt read my codes????? they are dumb.. the connection might be messed up to the code reader.. but checked it and seemed all wires were good

[mycologist]

i took it to 3 different places.. they couldnt read my codes????? they are dumb.. the connection might be messed up to the code reader.. but checked it and seemed all wires were good

I was also going to suggest that you are taking it to the wrong people.

Maybe if you can find a good tuner that knows WRX's they could just sort it out for you, but if you provide the information we might have a chance.

[zax]

First off you have neglected to include critical information including the model/year of car and modifications. For example, a stock 2L WRX should NOT be running 21 PSI of boost.

[mycologist]

First off you have neglected to include critical information including the model/year of car and modifications. For example, a stock 2L WRX should NOT be running 21 PSI of boost.

The new gauge probably reads high. I don't think that is what a log would show.

Notwithstanding that Ron was doing it in the midrange with a p&p td04, I agree with the advise that 18 would be a much better bet for us normal folks.

Edit: oh you said stock, sounds like it isn't but still waiting for the details.

[EJ257]

Notwithstanding that Ron was doing it in the midrange with a p&p td04, I agree with the advise that 18 would be a much better bet for us normal folks.

That depends on the cooling available. Considering that 18-19 PSI is fine/common on a StageII tune with the TD04, and 20-22 PSI is still not outside the efficiency range, with a quality TMIC (better cooling / less pressure drop), 21-22 PSI isn't all that aggressive. Obviously, this is dependent on timing/fueling, but you get the idea...

[mycologist]

Yeah I need a TMIC.

[zax]

None of those examples is stock. The surge line for a TD04-13t PnP is 24PSI IIRC. Well above what the internals will likely handle.

Edit: yikes I meant to say the surge line is 24 PSI at a standard 1atm ambient pressure. That's a 1.6 press ratio

[EJ257]

None of those examples is stock. The surge line for a TD04-13t PnP is 24PSI IIRC. Well above what the internals will likely handle.

Edit: yikes I meant to say the surge line is 24 PSI at a standard 1atm ambient pressure. That's a 1.6 press ratio

Been a while since I looked at a compressor map, but 24 PSI on meth/E isn't unheard of.

[mycologist]

None of those examples is stock. The surge line for a TD04-13t PnP is 24PSI IIRC. Well above what the internals will likely handle.

Edit: yikes I meant to say the surge line is 24 PSI at a standard 1atm ambient pressure. That's a 1.6 press ratio

OP profile -
Engine/Transmission mods:
forged pistons, eagle rods, cams, pnp heads, sti jdm pink injectors, fuel pump, aps intake, perrin down pipe, aps catback, sti top mount, perrin psrs, stage 2 clutch,


So actually 21 psi isn't completely unreasonable, although not a great TMIC.