I've had the SC installed for about 1700 miles. Pretty much since the install I've been getting CEL code P0420 which I thought meant there was some little guy smoking a bong in my engine, but it is actually [Catalyst System Efficiency Below Threshold (Bank 1)]. I'll clear it and it comes back about once every 5 days. For a week now, I have had the Forge 007 BPV, and NST9.5 lb pulley installed. Today when I started my car ,it turned over a little rough, and it is idling very low. I drove it for 45 minutes and it still idles low and rough at 350 to 450 rpms. Other than that it runs fine. Any ideas on the idle? or how to get rid of that CEL? Thanks!!!!!!

My engine upgrades are TRD SC, NST Pulley, Forge 007 bpv, Optima Battery, Untouched TRD intake that came with the kit.

 

Vac leak. Check your hoses.

 

I'm holding boost just fine up to about 0.65 to 0.70bar. 1 bar = 14.70lbs, so I'm hitting 9.5 lbs of boost consistently with no problems. I'd suspect that if I had a vacuum leak that I would be loosing boost. I guess I could test that theory by unplugging my vacuum line from my boost gauge and see what happens.

 

I'm gonna agree with complication and say vac leak. That souds like the culprit, especially since you recently switched BPV's. Check em all brotha.

 

Thanks for the info. I'll dig around and see if I can what I can find. I can imagine trying to find a small leak would be fun....

 

i had the same code when i got my s/c installed. the cat in the header blew so they had to replace it. i was running really rich cause they forgot to reflash it... now its reflashed and running fine but i doubt its the same issue since my idle wasnt affected. sounds like a vac issue.

 

i agree on the blown cat... i had the same mods (nst 9.5 and upgraded bpv). that is the code you are throwing so either get a new cat. or get an antifouler. i chose the antifouler route and it took care of the CEL.

as far as low idle... i think you would have a vac leak but then if you are reading full boost thats really strange. so i dont know about that one?

 

So... the idle problem just went away. It seems to be come n go because it was idling low, then fine, then low yesterday. Today it has been idling fine, so we'll see what happens. I paid the dealer to reflash the ecu, but if they didn't know what they were doing how could I tell if my ecu was actually flashed or not?

 

I had that same code, but it went away after I did the o2 anti-fouler trick, but I have an aftermarket header.

 

I plan on getting a header so the anti fouler is a must....

 

Did you unplug your pos side of the battery and wait ten min .....then plug it back in and let the car idle for 10min?

 

No I didn't.... What does that do? It's been idling fine since that day and I didn't do anything. I still get the CEL though.

 

^ it resets the ECU and lets it start learning all over again