I can see exactly where the P0420 comes on - it hasn't been showing up in any of my previous 15-20 datalogs.


No I don't have a test pipe. 2.5" Magnaflow Spun Cat with the Secondary O2 actually in the exhaust stream.

 

This code happens from the ecu running a cat check. Sounds like your maganflow cat isn't as efficient as a stock cat. I bet you sill see that this code happened during closed loop.

 

Here's a little update: I have not replaced my sensor and have not done the TSB relfash. I can keep the code away for ever as long as I don't hit VTEC at a low part throttle. It's that simple. By the fact that I can keep the code from appearing with my foot means it isn't the sensor.

I can also make the code come on at will by hitting VTEC at part throttle.

It's in the tune.

 

^interesting, good luck tuning it so that you can hit vtec w/o it coming on! Full throttle vtec is okay?

 

Yeah, full throttle VTEC brings no codes. Even a heavy-ish part throttle VTEC is OK. It's just a low/part throttle that makes the code pop. It's been over three weeks and two auto-xes with no code.

 

Have you tried to load the tuned calibration and see if it still does it?

I have been using the tuned profile till I have time to work on the partial throttle of my tune the way I like.
No codes whatsoever.

Don't forget to send me a log.

 

Giles didn't do a partial throttle tune for you?

 

I've tried all the tunes that are applicable that come with the Flashpro. I have no idea if Giles did a part throttle tune or not.

 

He did, It is just a little too aggressive for me.

 

He said he didn't on yours. He was using the throttle plate to see if you liked it otherwise he said you could use mine. Mine may provide good information about upper timing limits but it is too aggressive for track/autocross use.

If you tried the other tunes then I don't think it is the tune that is the issue. The last thing to try is the returned to sock mode. If you still have the issue you know it is the sensor responding improperly. It could be it is just has too much delay..