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1K views 16 replies 8 participants last post by  Krazy Horse 
#1 ·
I just sol my evo and bought my first cobra....and im loving it so far, but after two weeks of owning her ive got a cel code of po171......anybody run into this problem,and have any advice on a quick fix?
 
#2 ·
It's a o2 bank sensor. This is a generic code in nature and its just telling you that by the time air got to the o2 sensor it failed certain parameters. It doesn't necessarily say you should go replace your o2 sensor.

When I got the same code it was my CAI when I cleaned it I over oiled it causing my code to come on.
 
#3 ·
I disconnected the battery and cleaned the maf for starters, went through tons of start cycles, and here almost two weeks later the light came on, ran the diagnostics to find the same cel code p0171.....if an o2 sensor was bad, would it really take that long for the ecu to register again?
 
#6 ·
Lovely97cobra said:
I disconnected the battery and cleaned the maf for starters, went through tons of start cycles, and here almost two weeks later the light came on, ran the diagnostics to find the same cel code p0171.....if an o2 sensor was bad, would it really take that long for the ecu to register again?
Yes. I've seen the code before. I believe that is a downstream O2 sensor. If the car has the stock H pipe, get the O2 sensors checked. One is probably bad. If you have an aftermarket offroad Midpipe then you need a mil eliminator or a tuner to shut them off.
 
#7 ·
Car has bbk straight pipes to magnaflow mufflers.......if I needed mil eliminators, why when I bought the car, it took a month for this code to first pop up, figured it would have been on or come on quicker than that.....this is all new as im coming from the evo world...
 
#8 ·
Lovely97cobra said:
Car has bbk straight pipes to magnaflow mufflers.......if I needed mil eliminators, why when I bought the car, it took a month for this code to first pop up, figured it would have been on or come on quicker than that.....this is all new as im coming from the evo world...
It's how the sensors are. Mine use to take about a week before they would trip. Don't worry about it. Totally normal. MIL eliminator work, but a tuner is better obviously.
 
#15 ·
My gut feeling, which is usually puts me on the right path tells me to use the very specified MAF sensor cleaner, nothing else. Slowly introduce Seafoam into upper intake, and a can of the best fuel treatment out there-*"CHEVRON TECHRON" FUEL ADDITIVE - 12 Oz;
Lastly check all CAI rubber clamped connections. Check ALL vacuum lines for leaks.
 
#17 ·
There's a cheaper fix to the light instead of buying mil eliminators, buy 2 packs of the larger non foulers they use on old cars. Drill bottoms out of 2 of them then screw the drilled one on each side into non drilled ones and reinstall o2 sensors. The small hole into the pipe simulates convert delay to the pcm. Works every time for less than 20.00 $ and around 45 minutes work
 
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