I bought this car about 3 months ago and had an issue with the cam shaft position sensor (easy fix). Then come to find out that my gas mileage was worse then my Dodge 1500. It threw a code with the O2 P0171. Put an O2 sensor in it to fix that only to find another issue that really blows my mind. It only happens when it starts up after sitting for a few minutes. Starts fine, however when I take off...about a quarter mile it will bog down like it's starving for air or fuel. I've replaced plugs, wires, filters and had a trans flush. But after 3 seconds it kicks back in and proceeds on like there was nothing wrong (1 back fire in the process). No power loss after that and it wont do it again until turn the car off. It will occasionally throw a P0132 code. I've checked the connection and the wiring and did a highpot test (what we call a voltage test at my engineering firm) on the wires and there are no breaks anywhere. I'm thinking the O2 sensor is shorting so high that it's starving the engine for fuel or flooding it...but it's only that first few minutes that it happens every time I start up the car and drive. Anyone have ideas on what to try next?

 

During installation of the sensor you must have done something wrong.

 

it does that to me too, when im at a stop my car shakes, sometimes it turns off by itself, also it accelerates by itself. let me know if u fix it

 

oh by the way i have po132 too.

 

P0171 does not strictly mean a bad O2 sensor; it just means Bank 1 is detecting lean. The more likely issue is something is causing the engine to be running too lean, and the O2 sensor is picking it up like it's supposed to. The P0171 code symptoms are that "you will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration." Seems to be about what you are describing, yes? The common causes are a dirty MAF sensor (CRC has a cleaner specifically for this sensor, and it works well. You'll need somewhere around a T25 security Torx bit as well to get it off IIRC.) or a vacuum leak downstream of the MAF sensor. Might try checking those two things out. More on that vacuum leak though...

Check to make sure there isn't a [large] hole in the PCV line. I just fixed that problem on a Ford Focus yesterday morning that was throwing the lean code as well, and has been for some time now. It had a 90° rubber elbow on one end of the line and the hole was in the inside of the bend, almost the size of a dime, so you couldn't see it just by looking around and you almost couldn't hear it unless your ear was very close to it. Was a bit of a pain to track it down since it was between the firewall and engine about 1/2 way down and the belts were a tiny bit squeaky, but ended up finding it. That car was idling high, causing it to jump forward while in park, but stopped and it would also almost die just idling amongst other things. I cleaned the MAF sensor first to see what happened, but after that did nothing to help, I found that leak and that was the problem.

A P0132 is an O2 sensor code and commonly caused by either "frayed or broken sensor wiring, or the oxygen sensor heating circuit is shorted out." Since the test passes, sound like you need to find if and possibly where it is shorting.


See above.

 

Well here's what I did so far. I had some spare time at work so I took the car in and traced the wires. I did another voltage test on the wires to see if there were any other breaks that I didn't see. So far nothing. I then checked the connectors and they were still in good working order. Then inspected the O2 sensor wires and unit. Still nothing out of the ordinary. Ran various test to see if there were shorts in the wire and there was nothing out of the ordinary there. If it comes back again, I'm replacing the connectors. Cool thing about working for an electronics engineering firm is I have both here.

I then went after the MAF. Took the Throttle body assembly apart to see if there was any crap in it. Nothing that looked different to me. However seeing I always thought CRC was the best **** on earth, I sprayed the hell out of it with the MAF cleaner. Put everything back together and started it up. It ran like **** at first, worse then it did before. Unless it was over a grand it idled for ****. I took it for a 2 mile run (pounding on it) and sat back and waited for the check engine light to come on (seeing I cleared it) and to my surprise I got no idle surges and no light. I let it cool down and tried it again. Still nothing. I'm hoping it was a dirty sensor. But seeing I just did it about 4 hours ago, I'll report back and let you know what happened.

Thanx darthroush for the insight.

 

I believe the can says to only give it a few blasts. I'm not sure if doing more than that can cause something bad to happen, but I thought I'd throw that out there.

YW either way though!

 

Yeah usually after CRC your car will run like a pile for a little bit.

 

My sxt does almost the same thing sometimes it will die for no reason out of the blue and sometimes it will want to take off when sitting at a stop light or drive thru. I think its just a neon thing in my op.

 

I've never had an issue in any of the cars I've used it on, including the Neon? Are you guys letting the sensor completely dry out before you run the car again?