Trent06

i have put about 100 miles on the car since i installed the test pipe and no CEL. today on my lunch break, the CEL light comes on. what is the plan of action from here?

Toyofan

its not your TP since you have the AP1. i have the same part and no CEL.

Kermdaddy

Get the code. we can't help you without the code number

AFs2k

How is it not the test pipe on an AP1... what difference does it make? I'm seriously asking.

I had a test pipe on my '05 for a little while and then it threw a code after about 100-150 miles on it. (may have been more)

It was P420 I think. Which is the O2 sensor. I just took it out, cleaned it and put it back, and reset the ECU. Haven't seen the code again. I got the 70mm with the CEL fix too. Go figure.

Toyofan

cuz the ap1 part has a longer nipple welded onto the entrace hole for the o2 sensor allowing the o2 not to be directlly in the path of exhaust gasses. The ap2 rewuires the same nipple or bung on it.

AFs2k

Most test pipes have the CEL fix... Mine was not directly in the flow either(Berk 70mm). I'd say it was about an inch to an inch and a half out of the flow.

Trent06

got the check engine light checked at autozone this morning. here is the read out:

P0420
Catalyst system efficiency below threshold bank 1

Probable cause
- a/f ratio concern
- air leak near H02S (heated oxygen sensor) bank 1
- ignition system concern
- faulty catalytic converter

mister x

Would moving the O2 sensor further out of the flow via a spark plug defouler help?

My Berk 70mm on AP2 throws a CEL (P0420) reliably after 6-7 engine starts, regardless of miles driven.

Kermdaddy

Do the test pipe fix with the spark plug anti-foulers. That should do the trick.

AFs2k

Take the o2 sensor out, clean it, then put it back in and reset the ECU. Like I said, it's happened to me before, I said the code you'd get and you got it...