ZTwentyAteU

iTrader: (12)

My cam only TA throws both bank one and bank 2 heater circuit codes and po300 misfire code. Car has new o2 sensors from GM, injectors, all sensors on motor(motor is about 6000miles old). I've tried wires, plugs, etc etc. I've even tried about 10 different tunes, including stock tunes. It throws the codes and is PIG rich all the time. It runs great at WOT and the o2s read right, but at part throttle and idle its way too rich, and the car gets 13-14 mpg highway.

Anyone have any ideas? Do I need to get another computer?

jimmyblue

iTrader: (11)

The heater codes are warning you that the O2s are not happy
(especially at idle & low cruise, where you also see the big
problems). I'd look at how you can improve the thermal
situation. Wrap the collector for maybe 4" before & after the
bung; open up the slots in the sensor maybe (with care).

If you reallocate the fuel trim cells to get them all in play
you can segregate the really crappy (low airflow) trimming
to where it won't step on your highway operation and so on.

GMCHammer

iTrader: (4)

Have you checked for intake/exhaust leaks? Also check to make sure your O2 heater fuse is not blown.

ZTwentyAteU

iTrader: (12)

Thanks for the reply's guys. I have never checked the heater circuit fuse, it has one? Haha never crossed my mind..how could I build these cars and not know that! Guess i'll check that tommorrow. As far as the tuning, i've pretty much done everything I could to get it right, it seems to always end up back the way it was.

Tonight I got up beside my buddys small cammed SS (.537 lift) with stock crap on it still, and he pulled a whole car on me in third gear. Pretty dissapointing on a car that used to make right at 400 at the back tires. I guess i'll try a few more things and have the car looked at by someone else, maybe i've missed something

khaotic

iTrader: (2)

Hey let us know what you find out, I was working on a car with simular problems, but had no codes, the trims would go to 25 across the board and both the 02 would loose voltage and all the numbers would be skewed.

I think a bad ground or burnt wire, cause what makes both 02 loose voltage ?

ZTwentyAteU

iTrader: (12)

When I got the car, someone had neglected to hook up the grounds on the back of the head and my MAF wasnt working, causing maxed out LTFT.


As far as these said fuses for heater circuit, where the heck are they? i looked through my boxes and just went ahead and checked everything, no blown fuses

I know every wire on my harness is good, I checked over and re-did anything that was frayed/burnt when I swapped engines, and the o2 wires were fine

DaddySS

Can you post up the tune - as stated above you need to get the mixture right at idle, low RPMs first.

GMCHammer

iTrader: (4)

In my 04 truck it was in the fuse box under the hood. Should only be one fuse.

John_D.

iTrader: (2)

The fuse will say "sensor" rather than o2 or heater.

I would test the heater 12 volt feed, at the connector at the o2 sensor, and see if you are getting power there. The answer to that question will set you up for the next step.

ZTwentyAteU

iTrader: (12)

thanks. I'm also going to HPH in Bowling Green wed for a dyno tune. Hope we can figure it all out then