Car was idling for about 15 minutes and never went into closed loop. Had it revved up to 2k for a few minutes and the temp was up to 220.

o2 voltage varied from mV 408-480, also switched back and forth between lean and rich.

maf 5
proper step lean
base PW (ms) 1.6
loop open
o2 crosscounts 16 to 33
iac 20
A/F learned - no
integrate 128

temp reads fine, so I guess the sensor is good. I don't know if the maf is reading right or if the o2 is varying enough.

Can anyone make any sense of all that?

no codes yet (had the battery disconnected before driving 15 mins out to my friends house where the scanner is.

Tomorrow I'll probably order the injectors, because they're the only thing left I can think of that's still leaking and causing the fuel pressure loss.

 

How were you reading the temp? The instrument panel temp gage and the ECM use different sensors.

 

if the motor was at operating temp & all your seeing from the O2 is .408 to .480 voltage swing at 2000 RPM, i believe that is your problem with getting into closed loop. with that little of a voltage change the ECM will think the O2 isn't hot enough for closed loop.

the O2 should go much higher & lower than that, at least down to .200 & up to at least .800.

 

The temp gauge from what I understand runs off the front left sensor. The rear right sensor is an emergency sensor that just kicks the fan on if the engine is overheating. That's what I've read anyway. (don't forget, I have a V6)

I can't think of any other temp sensors at the moment. If I'm forgeting one or what I said above is wrong let me know. Both sensors came off my 2.8 and everything worked fine on it. But I can certainly replace whatever sensor runs the ECM tomorrow easily enough.

When the engine was first started I wasn't there, and my dad ran it for about 20 mins without timing it. When I got home and started it, I ran it up to 2k and when the headers began glowing all the way down to the o2, I realized it wasn't timed and timed it. (unhooked est, 10*)

The o2 was new, along with the engine, and during the first couple days I was getting the SES light now and then. Then my timing chain broke. After I got it running again I checked the codes and had 13 and 45. That all pointed to the o2.

I figured the o2 was messed up from the extreme heat. I replaced it, but it was still sucking down gas and after a week I got the 13 again.

So I hooked a multimeter directly to the o2 today with the car warmed up and got the same .4 voltage I got last night with the $2000 scanner.

Check out my other post about the rich/open loop stuff. There's some more info there.