Exhaust/Boost Leak at questions.

[Merpin]

Alright... so I have installed, CP-E Catted Downpipe, CP-E Dual Catback, CP-E CAI, SU Turbosmart BOV, ETS 3.25" TMIC, and recently a prosport boost gauge T'd off the vacuum line to the BOV.

My boost gauge shows peak of 20-22psi then drops down to about 15psi when I go to WOT then drops to 13psi@5800 and settles at 10psi. Also it seems to fluctuate a lot between 3k-5.5k. The needle jumps between 10 and 20psi and doesn't hold a constant reading. Is this a problem of the boost gauge or am I seeing some sort of boost leak? Also, is this typical boost reading for what I have installed or does it seem low? I found a leak between the cold pipe and the TMIC and fixed that but maybe there are more leaks to be found...

Also, I keep getting the CEL P0421 Warm-up catalyst system (RH) efficiency below threshold ON 2 Catalyst. It always pops on on the freeway going around 60 in 6th gear, like 2-3k RPM. Would an exhaust leak at the downpipe cause this code to pop? When I drive it harder the check engine light stays away /shrug.

I waiting on getting the dashhawk so I can datalog but atm school has dwindled my play funds.

Any input/suggestions would be appreciated. Thanks.

edit: ignore confusing thread title :)

[FORZDA 1]

Alright... so I have installed, CP-E Catted Downpipe, CP-E Dual Catback, CP-E CAI, SU Turbosmart BOV, ETS 3.25" TMIC, and recently a prosport boost gauge T'd off the vacuum line to the BOV.

My boost gauge shows peak of 20-22psi then drops down to about 15psi when I go to WOT then drops to 13psi@5800 and settles at 10psi. Also it seems to fluctuate a lot between 3k-5.5k. The needle jumps between 10 and 20psi and doesn't hold a constant reading. Is this a problem of the boost gauge or am I seeing some sort of boost leak? Also, is this typical boost reading for what I have installed or does it seem low? I found a leak between the cold pipe and the TMIC and fixed that but maybe there are more leaks to be found...

Also, I keep getting the CEL P0421 Warm-up catalyst system (RH) efficiency below threshold ON 2 Catalyst. It always pops on on the freeway going around 60 in 6th gear, like 2-3k RPM. Would an exhaust leak at the downpipe cause this code to pop? When I drive it harder the check engine light stays away /shrug.

I waiting on getting the dashhawk so I can datalog but atm school has dwindled my play funds.

Any input/suggestions would be appreciated. Thanks.

edit: ignore confusing thread title :)

Did you install these parts yourself? The P0421 can be the cat, the front and/or rear O2 sensor, an exhaust leak (you would hear it too), etc. Any other symptoms out of the ordinary.

[Merpin]

Yah I've installed all of the parts myself. I can get the code to go away for a few weeks then it'll pop back up. I just read another thread about it and they cleaned the rear 02 sensor and solved the problem so I may just try that. As for hearing the exhaust leak, I'm not sure exactly what it would sound like but I have a feeling that it would be noticeable, heh. All I hear is just the damn injectors ticking and my exhaust which is almost obnoxiously loud now.

Maybe I'll just tighten the DP up to settle my mind lol.

[Merpin]

So I went and scanned it again and not only did I have p0421, I also had p0037 and p0038 which are rear 02 sensore reading low/high respectively.... Who knows now, I'd think that if the highflow cat wasn't working then it would read high not low. Could a cat failure cause both of these codes to pop?

[JaxJeff]

Alright... so I have installed, CP-E Catted Downpipe, CP-E Dual Catback, CP-E CAI, SU Turbosmart BOV, ETS 3.25" TMIC, and recently a prosport boost gauge T'd off the vacuum line to the BOV.

My boost gauge shows peak of 20-22psi then drops down to about 15psi when I go to WOT then drops to 13psi@5800 and settles at 10psi. Also it seems to fluctuate a lot between 3k-5.5k. The needle jumps between 10 and 20psi and doesn't hold a constant reading. Is this a problem of the boost gauge or am I seeing some sort of boost leak? Also, is this typical boost reading for what I have installed or does it seem low? I found a leak between the cold pipe and the TMIC and fixed that but maybe there are more leaks to be found...

Also, I keep getting the CEL P0421 Warm-up catalyst system (RH) efficiency below threshold ON 2 Catalyst. It always pops on on the freeway going around 60 in 6th gear, like 2-3k RPM. Would an exhaust leak at the downpipe cause this code to pop? When I drive it harder the check engine light stays away /shrug.

I waiting on getting the dashhawk so I can datalog but atm school has dwindled my play funds.

Any input/suggestions would be appreciated. Thanks.

edit: ignore confusing thread title :)

I get about the same boost readings I spike about 18 and hold around 13-14 .
Personally I would think thats around normal, I mean the car stock is only set at like 15.3. Also do you have your DSC on ?. With DSC off you will notice higher boost in 1st and 2nd .

[FORZDA 1]

So I went and scanned it again and not only did I have p0421, I also had p0037 and p0038 which are rear 02 sensore reading low/high respectively.... Who knows now, I'd think that if the highflow cat wasn't working then it would read high not low. Could a cat failure cause both of these codes to pop?


Sounds like the rear O2 sensor is flaking out. Remove and clean it real good with contact cleaner and try again.