On the way to school today, I stopped at a Chevron to buy a drink. I get back in and turn my car on to find a CEL. I get to school okay, and drive home (~50 mile round trip), even hit redline once, everything seems normal. I checked the code when I got home and it was a #45, which is "System Too Lean or Too Rich malfunction in the fuel monitoring systems" according to C-Speed. Can you guys please shed some light on some possibilities? There wasn't much in the archives about #45's.

Some history/info:
-Engine wise, I'm just running an open airbox (yeah its slower, but I like hearing VTEC), Tanabe Racing Medallion, Skunk2 Cam Gears, and Toda Spec A Cams. The latest mods were the gears and cams, in late January.
-I bent the valves in early January on a freak misshift, but it got fixed and the car was running perfectly fine until february (mentioned below). The repair also included the cams and gears installation.
-I did a tune up recently which involved a new cap and rotor, spark plugs, injector cleaner treatment (the kind that goes straight to the fuel rail), tranny flush, oil change, fuel filter, cluth fluid, and radiator flush.
-Note that I didn't do plug wires...
-Since early February, the car has had a low idle (~500) and it's been somewhat rougher at idle. I'm not sure if that's related, I've been told its an IACV problem.

That's all I can think of that might have an effect. I'm guessing it's running rich as opposed to lean because I can smell gas in my garage when I heat up my car in the morning. Thanks for any and all advice.

Also, would it be wise to reset my ECU?

 

as far as im concerned you should always reset the ecu and if it doesnt happen again then you dont need to worry about it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by frenchy &raquo;</TD></TR><TR><TD CLASS="quote">as far as im concerned you should always reset the ecu and if it doesnt happen again then you dont need to worry about it</TD></TR></TABLE>

Well, I reset it, but I don't really see that as a permanent solution to the problem. Could it be a bad O2 sensor?

I forgot to mention that I've had a hesitation problem too. It comes and goes, but it's enough for me to feel...

 

Wow no one else?

 

I actually have this exact same problem right now. It has made my gas mileage drop significantly. I replaced the plugs, fuel filter, and used some injector cleaner with no results. I believe it is the primary o2 sensor. I am going to go get a replacement this weekend and I will update you on the results.

Dave

 

Replacing the primary o2 sensor fixed the problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dmannGSR &raquo;</TD></TR><TR><TD CLASS="quote">Replacing the primary o2 sensor fixed the problem.</TD></TR></TABLE>

Cool. Where'd you get one?

 

I had the same hesitation problem with CEL code 45. I replaced my o2 sensor with a universal Bosch o2 sensor, reset my ECU, and the problem was gone.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Calsonic180 &raquo;</TD></TR><TR><TD CLASS="quote">I had the same hesitation problem with CEL code 45. I replaced my o2 sensor with a universal Bosch o2 sensor, reset my ECU, and the problem was gone.</TD></TR></TABLE>

Was it your primary O2 sensor? and was it hard to do (if you did the work yourself)

 

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

Was it your primary O2 sensor? and was it hard to do (if you did the work yourself)</TD></TR></TABLE>
Yes it was the primary o2 sensor. I did it myself. The hardest part was getting the old sensor off, it was rusted on there. Then the next hard part was splicing the wires for the Bosch sensor. If you get an OEM sensor, then it's just simply plug & play. Took me about an hour to do.