Running rich? Sooty exhaust, low gas mileage.

[3rzrunner]

Alright guys, I've got a weird problem with my runner.
First off, recently it has been drinking more fuel than average, and it feels like it has slightly less power than usual.

The truck is a 1997 4cyl 3RZ-FE, 5speed manual.
It has rebuilt LCE fuel injectors and seals. Ive done a Valve adjustment, LCE long tube headers, Vibrant SS highflow racing cat, JBA cat back exhaust, Paradise racing spark cables, NGK iridium plugs, and a K&N filter. also has newish Denso O2 sensors.

Recently it has been drinking more fuel, and the biggest thing is the quarter bumper is getting really covered in soot, if i rev it up, and shift from 3rd to 4th it puffs out a bit of black as well.

I've connected it to a scan tool, there is no codes and everything looks normal, o2's seem to be functioning properly, fuel trim is good, tp is 11.4% at idle, Maf seems good.

I dont really know what else to try at this point, anyone have any ideas of what could be going on? what could be causing this much soot?

Thanks guys

 

[19963.4lsr5]

It's running in closed loop, correct?


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[3rzrunner]

It's running in closed loop, correct?


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It is running in normal closed loop, and when you go to WOT it does switch to open loop, or when u are in gear and lift off the pedal going down hill, it switches to open loop.

 

[Scramble]

Mine gives off a lot of soot too. Bumper & Polished tip get black, no codes, no idiot lights. My MPG's are the same, no loss of power. It started when I went to headers, HF cat & exhaust. I'm not sure if I'm running rich or if's because of the larger exhaust? It's gotta be a 3RZ thing. Maybe post in that thread.

 

[19963.4lsr5]

If you have any gaskets leaking in your headers etc the reversion will draw fresh air into the exhaust and trick the O2 sensor into adding more fuel.


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[gamefreakgc]

x2 on checking for vacuum leaks. Causes a lot of rich conditions.

 

[19963.4lsr5]

x2 on checking for vacuum leaks. Causes a lot of rich conditions.

I'm referring to leaking exhaust gaskets.


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[3rzrunner]

thanks for the replies, im going to check my header gaskets tomorrow and let you all know.

 

[19963.4lsr5]

thanks for the replies, im going to check my header gaskets tomorrow and let you all know.

I've sadly never had header gaskets or collector gaskets that didn't leak without doubling them up or going copper.


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