Afternoon everyone, got one for everyone. So my clubby has been annoying me with a stupid p0420 code, which comes and goes. Well i finally today was able to get it to clear completely with my scanguage, no CEL once i turned the car back on. I had to run some errands at lunch, so i hop in her, get her up to temp, and start giving her a bit more, boost starts creeping up into the 15-16 lbs, give it a bit more 17-18 lbs, hold it down and 20+lbs of boost did see 22 lbs in 6th gear but had to let out of it approaching going to jail speeds. Before the most i saw was 15.5, so my question is it possible that i have a stage 2 tune and how would one go about finding out. As for mods i have g+ plus intercooler, forge noise maker delete, sneed speed turbo muffler delete, aFe drop in, alta boost spring, updated DV, forgery DV spacer, blocked PVC passenger side, OCC driver side. I am the 3rd owner of the car and did find evidence that there was an AEM CAI on the car before.

 

If you are getting ~20psi of boost, then for sure its been tuned. Which tune... that could be anyone's guess. I would bet its a stage 1 if you are seeing P0420 codes come up. Stage 2 tunes usually turn the monitor off for the primary cat. It is possible its a Manic tune, but I don't think you could tell unless you could ask one of the previous owners.

 

i am seeing 20 lbs in every gear now, expect for around 22 in 6th gear. Got to drive her home, so i will get so more numbers as i can watch, wish the scanguage could log data.

 

So for sure 20 lbs in all gears and overboost in 6th gear appears to be 22 lbs. Had an Evo in front of me on way home and we hit 140 mph, I let out once I realized how fast we were doing.

 

Another ? would a stock downpipe on a stage 2 tune cause a p0420 code? Probably not but doesnt hurt to ask. Hopefully one of the tuners or a vendor could shed a bit of light.

 

I must have missed it that you were still running the stock cat down pipe. If you have a stock down pipe installed, you should not get a P0420 at all... unless the monitor is actually telling you that the cat is bad, or that the down stream O2 sensor needs to be replaced.

My understanding is a stage 2 tune requires a high flow down pipe, whether that be cat-less or high flow cat.

 

I think it is a stock cat, maybe I need to take that damn heat shield off and see what is really going on. I hate been a third owner and not knowing the previous owners. My last 4 cars before this I was either the original owner, the was one 3 of them, or 2nd owner and I personally knew first owner and that covers my last 20 years.