Running VERY rich (9.8:1) need help diagnosing

[SirThomas88]

I went to the dyno shop again today. I'm running even richer now with my OBX Headers and Jim's Fuel Mod than I was before!!! I'm also throwing a CEL P1410 since the header install. But that's probably unrelated. My car is n/a and I'm going to slap in a S/C in a couple weeks but I need to figure this problem out first.

P1410 = Valve position sensor fault (malfunction)

You'll see with the dyno from today posted below that there is a huge variance between runs, and my AFR drops as low as 9.8:1 AFR!!! Something is making my computer freak out and dump fuel into my engine. You'll also notice that the Closed Loop is running fine at 14.6:1 AFR

CURRENT Dyno 2 Date: 3/11/10 (w/ OBX headers and Jim's fuel mod)


PAST Dyno 1 Date: 3/5/10 (stock manifold and exhaust w/ Injen intake)


Here are some possible causes that people have mentioned (though no one seems confident about any of these being the problem)
1. Dirty MAF (cleaned it now, but problem persists)
2. Injen intake causing problems (doubt it!)
3. O2 Sensors dirty/faulty
4. Injectors stuck open
4. Broken EGR (EGR is snapped which might be causing the CEL but probably not the richness, from what I understand. Probably not the cause because I was already running rich before it snapped i think)
5. Disconnected vacuum line.
6. Leaking manifold/exhaust (This was a problem before, but entire exhaust and gaskets has been replaced with OBX and JP, should be fixed)

If anyone has any experience, suggestions, or ideas on which of those listed you think it may be or something not listed, please let me know. Any input is greatly appreciated. I know if anyone has the answer... it's the awesome ToyotaNation community.

[chronoti]

get a jaw wideband kit, better for tuning anyway

[bigbird]

was this cel on before you went to the dyno. if so the car is in limp mode in which it dumps fuel to prevent damage.

im actually about to leave for agile now

[camry6]

Originally Posted by bigbird

was this cel on before you went to the dyno. if so the car is in limp mode in which it dumps fuel to prevent damage.

im actually about to leave for agile now

I agree, you have to fix the CEL code cause first. The ECM runs rich to err on the side of safety from running lean. That's why people wonder why their car starts burning more gas when the light comes on, and for some reason beyond my understanding, a lot of mechanics will tell customers that there is really no reason to fix it.!!??

[SirThomas88]

The CEL was not on before I got the exhaust put on. I think when the exhaust was put on the guy leaned on the EGR and accidentally snapped it because it is definitely snapped and the wires are exposed. I'm going to put on a new one soon.

I was already running rich before the CEL light, but that MAY have been because of my incredible front manifold exhaust leak which is now fixed. Before the CEL, my AFR dropped as low as 10.1:1 as you can see in the dyno results. After the CEL light my AFR got worse and went as low as 9.8:1

So maybe if I'm lucky, it's as simple as the CEL issue replacing the manifold leak issue keeping me with very rich conditions. I hope you guys are right that it's just the CEL causing a limp mode!! I'll assume you guys are right until I can get the new EGR connection on and test it out.

Thanks for your input!

[bigbird]

if you got an EGR valve position sensor fualt code popping up the car WILL go into limp mode and limp mode WILL cause rich and retard conditions. replacing it should get rid of that code.

I didnt think about it till now but i felt it when we were dropping off my tranny. when you had to pull in front of that truck the car was lagging like crazy. I didnt even put 2 and 2 together till now.

[chronoti]

44k resistor should bypass the sensor (and keep the egr closed)

[EEngineer]

wow that sucks. your na numbers are not too healthy =[

well, EGR is definitely a problem here cuz 1MZ has a very much over-used EGR...consider deleting it and run 94 from now.

do replace your O2 sensors, or at least torch them a bit.

[SirThomas88]

Wow I hope you guys are right and it's just the EGR! That would be great if that fixes it. I'm not too confident that it is. Something tells me it's not that simple...

I clear the codes when I start my car and they stay off until I turn off/on my car again, but I don't notice any difference in performance. And with a 9.8:1 ratio that's causing a 20-30HP loss, I should definitely notice a performance gain when the problem is fixed.

I'll post what I find out once it's fixed.

[bigbird]

Originally Posted by EEngineer

wow that sucks. your na numbers are not too healthy =[

well, EGR is definitely a problem here cuz 1MZ has a very much over-used EGR...consider deleting it and run 94 from now.

do replace your O2 sensors, or at least torch them a bit.

we have emissions we have to pass here in MD and no 94 octane pumps. the best colution since he's obdII is if he deletes the EGR he must put in a resistor to clear the CEL and hope they dont sniff. other then that he can just replace the EGR and all will be well.

Originally Posted by SirThomas88

Wow I hope you guys are right and it's just the EGR! That would be great if that fixes it. I'm not too confident that it is. Something tells me it's not that simple...

I clear the codes when I start my car and they stay off until I turn off/on my car again, but I don't notice any difference in performance. And with a 9.8:1 ratio that's causing a 20-30HP loss, I should definitely notice a performance gain when the problem is fixed.

I'll post what I find out once it's fixed.

ive been in lots of auto 1mzs and i can tell you when we went for that ride and tried to pass that truck...something was definatly wrong. just because clear the code doesnt always mean your car will work 100% when you restart it. this may not fix it, but it has to be fixed to rule it out as a cause.

[chronoti]

2 trip "trip logic" the error has to be there before it sets the cel, but it knows something wrong and killing the output,

try looking at what the ecu is reading the af mixture is vs. real, if the ecu shows it tuning for 14.7 and your getting 9.8 welll you found your problem