My 98 accord has the check engine light every time I fill up. I tighten three clicks too. Then after about 3 days the cel shuts off...???? I went to the local shop and the code comes back to Catalytic convert. Should I replace the gas cap? the cat convert? sensors?

 

I would start with the cap b/c that is going to be your cheapest route.

 

Get the code #??

A gas cap that's not airtight would set P1456.
A bad catalytic converter would set P0420.

I had AutoZone read a code for me once, they read the actual code # OK. But then the guy came up with an amazingly creative story for WHY it came up with that error.

 

autozone did read the p0420 code for bad cat convert. but why does the cel shut off after 3-4 days after filling up on gas?
should I worry... or just get a new convert installed?

 

Got less than 80k miles? Emmissions system warranty is 8yr/80k imles. Maybe it'll be free - at least it's worth a phone call to the dealer to ask.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scootrrydr &raquo;</TD></TR><TR><TD CLASS="quote">autozone did read the p0420 code for bad cat convert. but why does the cel shut off after 3-4 days after filling up on gas?</TD></TR></TABLE>That part is pretty strange. But just as one dumb idea... Try filling the tank not all the way, the next few times. I'm taking a wild guess that if you try to overfill your tank you saturate the charcoal in the EVAP canister. Maybe that leads to over-rich running for a little while?

If I had to pay $$$ for a new catalytic converter, I'd want to be pretty sure that it's really the problem. I wouldn't buy a gas cap unless it was throwing P1456.

 

My CEL is on after I filled up with 91 octane. I normally run 87, but the pump was out of order. Is this normal? My CEL has been on since Saturday.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PH3593A &raquo;</TD></TR><TR><TD CLASS="quote">My CEL is on after I filled up with 91 octane. I normally run 87, but the pump was out of order. Is this normal? My CEL has been on since Saturday. </TD></TR></TABLE> no something else would have to be your problem because switching octane wouldn't cause a cel

 

I never knew a bad gas cap can light CEL.

I saw a car with a rag instead of a gas cap.

 

yeah most newer cars will do that cause its "not emission friendly to have gas fumes going into the ozone"