Okay, background:
*1998 Accord LX 4 cyl - no modifications
*recently had a 2001 4 cyl engine transplanted into it (1000 miles ago)
*pass state inspection with flying colors on Saturday
*changed the battery on Sunday
*added gas on Monday (engine was off during refueling)
*CEL comes on 5 miles after fill up (hmmmmm...)
*Checked to make sure gas cap was on tight, it was, but I cranked it a few more clicks (incidentally, my state inspection does look for a leaky gas cap, and since it passed inspection 2 days prior, I'll assume the gas cap is fine)

*Shorted pins 8/13, and pulled code 67.
*67 is not in Helms AFAIK, but searching HT I turn up "Catalyst Below Threshold"

1. Can someone confirm what code 67 is?

2. If it is indeed a faulty cat, searching the archives tells me that the cat is covered for 8/80K? Correct? (I've only got 73K, so that would mean the dealer gets this one, on AH's dime, not mine!) I would check my manual, however the car was purchased used, and I don't have the warranty manual.

3. Just in case I misread the code...what is DTC 76? It's not in Helm's either. I'll verify the code tomorrow, but I checked it twice, and it was 67...but just in case I'm wrong...please let me know what 76 is.

 

Oh, the reason I'm asking for confirmation is because I think I made a wrong turn somewhere in my research. The car passed a state emissions inspection this past weekend. I highly doubt a cat failed in 2 days, and is now throwing codes. Something doesn't add up here.

 

The Helm book puts the codes in order by OBD-2 codes, not by CEL codes.
P0420 (67) catalyst low efficiency
I can't find a code 76.

The ECU uses the 2nd O2 sensor to measure how good the cat is working. I think a bad O2 sensor can trigger this, even if the sensor isn't bad enough to trigger a code 63.

 

You need to replace your catalytic converter. My 98 did the same at 95K miles. Try to talk to the service manager at the closest honda dealership for assistance and warranty coverage. yes it's 80k warranty.

 

I don't know what your state inspection does, but in Md the emissions test - which is part of the inspection - involves running the car for like 2 mins with the OBD2 scanner hooked up. if there are no codes, you pass, if there are codes, you fail.

code 76 is cyl 6 misfire - but good luck finding cyl 6 on an I4

 

LOL! So the cat went south...but it's strange. Our emissions inspection puts the car on a dyno and measures emissions around 2-2.5K rpms I think.

I hope the dealer doesn't give me crap about the 2001 engine that's sitting in the engine bay.

I suppose it's wise to replace the O2 sensors while they are in there fiddling with the cat? Based on my search, the O2 sensors and EGR valves are a PITA too. :-/
(edit: meaning they fail quite often)

 

Jim,
IIRC, the O2 sensors are not covered under the 8/80K emissions, right? I would rather not **** money away at the dealer, if I don't have to...so if this is a distinct possibility, I might swap out the O2 sensor first. Although...it's cold as hell outside...! :-/

Thanks!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">
The ECU uses the 2nd O2 sensor to measure how good the cat is working. I think a bad O2 sensor can trigger this, even if the sensor isn't bad enough to trigger a code 63.
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It's very rare for a bad o2 to set a catalyst efficency code. (I have seen a couple.) 99% of the time it is a bad cat. (Actually it is a cat starting to go bad when the code first pops up. They will still work pretty good for a while.)

 

Any estimates on how long it may last after the first CEL?

I just cleared the code, and drove about 30 miles. The code hasn't come back...yet. I'm kinda hoping it does now...I've got 6K left on the emissions warranty, and I sure as hell don't want to have to pay for this.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RKA &raquo;</TD></TR><TR><TD CLASS="quote">

I just cleared the code, and drove about 30 miles. The code hasn't come back...yet. I'm kinda hoping it does now...I've got 6K left on the emissions warranty, and I sure as hell don't want to have to pay for this.</TD></TR></TABLE>
The ECU has to detect the problem on two consecutive drive cycles before it will illuminate the CEL.

 

Ah, thank you! I just reread the manual, and found the code (doh!). Indeed, the first suggestion is to reset the code, and perform a test run with the scan tool attached to see if the cat passes or not. If it does pass, the manual suggests no further action.

Since I don't have a scan tool, I guess I'll just continue driving and see what happens.