Help with check engine light
06-13-2007, 11:17 AM
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Help with check engine light A little background first: I recently changed my clutch, and in the process I had to remove the headers. I replaced the drivers side 02 sensor because a bare wire was showing from rubbing on the frame. The pass. side O2 sensor looked fine and had no issues. I'm also not running cats but still have the rest of the emission hooked up (AIR pump)......this is on a 99 Corvette.
So now I'm finished with that and I'm driving the car. I keep setting a P0154 DTC. Now I haven't gotten a chance to hook up HPtuner to the car yet, so no data is available right now. I'm going to do that tonight. I did look for wires that were disconnected and didn't see any.
Besides the check engine light, the fuel mileage is down about 25%. Also, I can hear what sounds like the AIR pump running constantly. I think the AIR pump running may account for the drop in fuel mileage as the O2 sensor may be reading lean, so the computer is compensating by dumping in more fuel. The light will come on about 5-10 minutes after I've been driving. If I clear it, it will come back on the next time I drive the car.
I don't know if the AIR pump running constantly is causing the P0154 or if the code is causing the AIR pump to run.
When I scan my computer, look at the car, and anything else, what should I be looking for? I really don't have a lot of experience with HPtuner yet, so help me out.
Thanks for the help
Derek
So now I'm finished with that and I'm driving the car. I keep setting a P0154 DTC. Now I haven't gotten a chance to hook up HPtuner to the car yet, so no data is available right now. I'm going to do that tonight. I did look for wires that were disconnected and didn't see any.
Besides the check engine light, the fuel mileage is down about 25%. Also, I can hear what sounds like the AIR pump running constantly. I think the AIR pump running may account for the drop in fuel mileage as the O2 sensor may be reading lean, so the computer is compensating by dumping in more fuel. The light will come on about 5-10 minutes after I've been driving. If I clear it, it will come back on the next time I drive the car.
I don't know if the AIR pump running constantly is causing the P0154 or if the code is causing the AIR pump to run.
When I scan my computer, look at the car, and anything else, what should I be looking for? I really don't have a lot of experience with HPtuner yet, so help me out.
Thanks for the help
Derek
06-14-2007, 02:12 AM
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I did some monitoring with HPtuner tonight
So bank 2 02 sensor is pretty much constant at around 450mV, which according to the manual would be a problem..."inactivity" or something to that effect.
However, Bank 1 is cycling between 0 and ~500mV (don't remember for sure...but diffenatly down to 0) Also, the Bank 1 LTFT is maxed out at 25 (If I turn it to closed loop) if I reset the LTFT and turn on closed loop it quickly goes back to 25. It also starts missing and running poorly in closed loop. The bank 1 injectors also begin to increase in duty cycle.
So I'm thinking my gas mileage is down because its not going into closed loop mode and because the computer is adding a bunch of fuel.
I checked the wires connected to the 02 sensors and all looked well.
Anyone got some more ideas or more checks to do?
So bank 2 02 sensor is pretty much constant at around 450mV, which according to the manual would be a problem..."inactivity" or something to that effect.
However, Bank 1 is cycling between 0 and ~500mV (don't remember for sure...but diffenatly down to 0) Also, the Bank 1 LTFT is maxed out at 25 (If I turn it to closed loop) if I reset the LTFT and turn on closed loop it quickly goes back to 25. It also starts missing and running poorly in closed loop. The bank 1 injectors also begin to increase in duty cycle.
So I'm thinking my gas mileage is down because its not going into closed loop mode and because the computer is adding a bunch of fuel.
I checked the wires connected to the 02 sensors and all looked well.
Anyone got some more ideas or more checks to do?