09 HHR: P0420 diagnosis
09 HHR: P0420 diagnosis
From the FSM. It describes a 2 stage cat efficiency check procedure. The first step is driving and the second step is idle. It won't do the idle test until the driving test meets parameters. There are two PIDs in the data stream that let you know what is happening.
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Re: 09 HHR: P0420 diagnosis
Reports are that so far the check engine light has not returned since installation of the stock cat. Permenent code had not reset after 3 days of mild normal driving use, not sure how often it's been used since then. I'll try to check codes tomorrow since I'm supposed to pick up the excavator in East Lyme for use at the scout camp on Sat.
Re: 09 HHR: P0420 diagnosis
It moved from permanent to “stored”. So there’s “1” code, but mil status is still off. I don’t understand.
Re: 09 HHR: P0420 diagnosis
That's probably good to go then. The correct thing was to reset codes after running a successful cat readiness drive cycle. I know we discussed not wanting to remove the other monitors but that would have probably been the quicker, easier option. I know you were worried Paul would disassemble the vehicle again to make everything ready.....