P0171 Help!!!

[esleeck]

OK,
I've had this code for a while now ( p0171). The light is on constantly never goes off even right at start up its on. Originally everyone said primary o2. I replaced that and still no luck. Also car has recent (within 5k miles of when code started) tune up including plugs, wires, disty cap, fuel filter etc etc. The car seemed to idle kind of rough almost like it wants to stall but when I'm driving it seems fine. My fuel mileage has dropped to low 20s a gallon. Also I can smell gas through the vents when I have my heat or A/C on. I do have the Honda shop manual and have looked at the flow chart for this code but I dont have some of the tools required to do the diag ( like a fuel press guage or a vacuum pump to check the EVAP purge control solenoid valve) . I am wondering if anyone has experienced these same symptoms and if so what corrected it. I need to get my car inspected and it won't pass with a cel.

 

[xxsenceo89x]

my guess would also be o2 sensor. check the wires that go to the ecu. try switching the primary and the second

did you clear the code when you put the new one back in?

 

[esleeck]

yes, I did clear the code when I replaced the o2. I also cleared it a few times just for the hell of it and it always comes back as soon as it goes through the cycle.

 

[96733]

yo yo yo

a p0171 means you are1 running lean. not necessarily does it mean that you have to change your o2 sensor. although that may be the problem i would check else where first. when engine running lean check for hoses and vacuum leaks. clogged injectors or any where in the fuel system that will prevent it from operating properly. yeah i would also check fuel pressure etc. per workshop manual good luck.

 

[esleeck]

I did check for vacuum leaks and didn't find anything. Also when I created a small vac leak the idle changes a lot so I'm pretty sure that I ruled out a vac leak. I used to work on cars for a living just for a short few years and this code was almost always a damn vac leak but of course not in my case. All of my injectors seem to be clicking normally, I used the long screwdriver to the ear method. This of course doesn't tell me if one is clogged, what would be the best way to check for a clogged injector? So right now I'm kind of leaning toward either clogged injectors, bad fpr, or maybe the EVAp purge control solenoid. But I am still stumped on how I am able to smell gas inside my car through the A/C vents. I'm so frustrated right no I'm almost ready to just give up on this pos.

 

[96733]

possibly a bad iac valve stuck? pretty sure if evap purge solenoid was stuck you would have an evap code. i would monitor pids to see if map sensor is reading correctly and monitor fuel trims again. maybe map sensor is faulty causing computer to make engine run lean?

 

[green_ace]

Check your Fuel Pump.

 

[esleeck]

I think thats the next thing that I have to eliminate. Does anyone know if and where I can get the special fitting required to connect a fuel pressure tester gauge or do I have to rig something up in the line with a tee??

 

[JPW77]

esleek, did you ever get this fixed? I have the same problem with my 96 Civic LX and I'm trying to determine the best course of action. I bought this car for better gas mileage only to get it home and find out it's getting in the mid 20's which is horrible. How can I check the O2 sensor to see if it is bad?

 

[esleeck]

Still hasnt been fixed... I dont really have the money to mess with it right now I'm pretty broke for the next few weeks due to not working for the last few weeks. But to everyone else Im still open to suggestions on why the hell am I smelling raw gas inside the car??? because I have no idea

 

[JPW77]

That sucks man. I just ordered a new primary o2 sensor to try on mine. I also have a cracked exhaust manifold that I need to repair or replace. Maybe you could take a look at yours and see if you have the same problem?

 

[JPW77]

I patched my exhaust manifold with some ThermoSteel and installed a new primary O2 sensor and all is well now. My fuel mileage went up considerably and no more CEL. I hope you've gotten yours figured out by now esleek.

 

[CTRowner]

Fixed mine

Had trouble clearing this code P0171, replaced basically everything on car and still no joy, in the end a £5 can of carb cleaner on the throttle body fixed this code. shame I didn't do this first I could have saved a lot of time and money.

 

[gugiey]

Had trouble clearing this code P0171, replaced basically everything on car and still no joy, in the end a £5 can of carb cleaner on the throttle body fixed this code. shame I didn't do this first I could have saved a lot of time and money.

I highly don't think that's gonna keep the light off for long .

and you skipped passed the number one diagnosing tool by not using the service manual trouble tree. and wasted a lot of money by throwing parts at it . a vacuum pump is cheap . and you might need it again. a oil pressure gauge are not to expensive. I would think you could borrow these tools from your local parts store to .

I had this same code . plus p0172
and diagnosed both of them for under 200 dollars. these tests take 5-10 mins and give great insight to what the problem is .

 

[99eksi]

yes, I did clear the code when I replaced the o2. I also cleared it a few times just for the hell of it and it always comes back as soon as it goes through the cycle.

i had same problems, it was the connector from the wiring harness side was corroded. cleaned it out. worked for me. on my other hondas when i go with a test pipe i plug the hole where the o2 would go and hang my o2 in my engine bay. it tricks the ecu to thinking that the cat is cleaning the gases that come out of my motor u should try it. also leaking exhaust can throw that code even a little leak that u cant hear. replacing o2s isnt always gonna work

 

[mymmeryloss]

Clean all sensors. Run seafoam and flash your ecu. Change both o2 sensors at the same time...


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