A/F guage

[96spyderman]

I got my A/F guage installed today and it seems to be running correct... I read a thread just a little while ago about the led's bouncing back and forth which mine does at idle. It actually goes from extreme lean to the other end of stoich but not into the rich.
When I accelerate and the rpm's get up there it goes rich to lean and then it "goes off the chart" if I let off, it comes back in the lean side and then goes to rich and then starts bouncing around again.
About 70% of the time it is in the lean side.... could this have something to do with my new denso iridium plugs?
The old plugs had a rust colored residue on them......what does that mean? There wasn't much wear down on them and they are about a year old. Please HELP!?!?!?!?!?lol

[96spyderman]

Another question... could having a OBX high flow CAT in which screws with the 2nd 02 sensor have anything to do with the readings? I would like to get an 02 sim to get rid of the CEL.
I've heard you can take out the 2nd 02 sensor and wrap it in tinfoil and keep it in a hot place... what would that do and would it change the reading on the A/F guage?
I installed the guage as how explained on VFAQ.com...very simple to follow and do!!!

[kjewer1]

Rear O2 has nothing to do with fueling or what you see on that guage, its just there to verify for the ECU that the cat is working. What you decribe seems perfectly normal. Pegged rich at full WOT and over say 4-5k rpm is normal. The oscillating you see at idle and hopefully cruise as well is a sign that your O2 sensor and ECU are working properly to maintain the proper AFR under those conditions.

[96spyderman]

No it pegs lean at WOT and actually all the leds are off!!! After letting off the gas it comes back in the lean and then starts bouncing around.
The only time it goes to the rich is right when I hit the gas and then goes more to the lean side.

I do have some boost leakeage at about 10 psi+... I would assume that if it was leaking wouldn't it run rich from that?

[kjewer1]

Yes, a leak would make it richer. There no way it can be full lean and still run, so there is something going on there. You would really need trace data for that sensor to be able to see. Bad sensors can act like that, but its hard to say without seeing a trace of it from a logger.

[96spyderman]

Would checker auto or auto zone be able to test to see if the 1st 02 sensor was goin bad?
Or is that something only a pocketlogger could do?

I regapped my plugs...iridiums... and it seemed to run a little more on the rich side by just a little. If curious about the iridiums see the thread... Denso Iridiums...
Thanks for all the help!!

[o0_the_0ne_0o]

wot should peg it and when ur cruising it stays mostly low

[kjewer1]

An OBD2 scanner probably wouldnt pick up on a bad sensor unless its bad enough to trigger the CEL. Sometimes codes are set with no CEL though. Those places usually check it for free, so it wouldnt hurt to try it.

[dsmodder]

so does that mean you dont need a second o2 sensor and you can just disable the CEl itwould produce with dsmlink? just curuious cuz im like a week away from startin my exhaust

[96spyderman]

If you are going to eliminate the 2nd O2 sensor you will get a CEL... I put in a high flow cat and now the 2nd O2 is reading different... Get an O2 simulator... it sends a signal to the ecu that everything is AOK...

[96spyderman]

Originally Posted by o0_the_0ne_0o

wot should peg it and when ur cruising it stays mostly low

Do you mean that at WOT it should peg lean? or rich?
Mine is peggin lean at WOT... when I accelerate slower/moderately with little to no boost it stays mostly in the stoich area.
Yes when i'm cruisin it just kinda stays in stoich and lightly rich.
I thought that at WOT it should be rich....?