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Help with CEL codes and erasing them.

3K views 17 replies 5 participants last post by  1987davids 
#1 ·
I have a 2000 P11 and I realized i'm getting terrible gas mileage so I figured I would get my codes read and see if they could be what is causing my issue.

The 2 codes: P0141, P0325

I have code P0141 for O2 Sensor heater circuit malfunction, but what what doesn't make sense about this is why would only the heater go out and not the whole o2 sensor?

The only other code I have is P0325 for Knock Sensor which I read online that it could be caused by this O2 sensor being out?

Link to images of o2 sensor and knock sensor. https://imgur.com/a/UwDs0

I also cleaned my MAF sensor just to be sure it wasnt throwing anything weird.

I dont have a scanner atm but is there any way to just erase the codes? I looked at my ECU and there is no screw or LED to display anything, also looked up ECU reset procedures for this model and cant find a single thing on this car lol.

Any help at all would be appreciated, also any information you may need I can get.
 
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#2 ·
I have had 2 rear O2's go on my 2002 G20. Heater element was the problem on both. Don't buy a cheap one, they are garbage. I bought a Bosch replacement for close to $100 and it was working great until water got into the "Weatherproof" splice connector. So try to find a replacement with the factory end. If you go to a auto part store they can clear your codes (usually free). I would fix the O2 problem before the knock sensor and see if the P0325 comes back. The knock sensor is pain in the but to change.
 
#3 ·
But my issue is this car now has 320,000 miles and im feeling its not worth more money but its still running strong. The main issue atm is the gas mileage and a slight oil leak but after that its a great nice car.

Opinions on why my mileage is bad? Any tune ups you think i should do to keep her running?
 
#4 ·
coolant leaking? look at the reservoir for it if its low . burned up my o2 heater when head gasket went. some crushed silicia gel pack beads from the new shoes or half a bottle head gasket stop leak 28 bones from walmart not the cheap clumps of shit in a bottle. works great.. and an 02 sensor that ohms at spec from the scrap yard if you dont want to spend the dough
 
#5 ·
I had a heater bose leaking for month but a slow leak would just drip down the oil filter and the entire back of the engine. I got the leak fixed but a week later is when the light came on.

Would this be a good replacement for the o2 sensor?
https://m.ebay.com/itm/Oxygen-Senso...706362&hash=item1e88362af8:g:9o4AAOSwVRpZpoAt

I also have a small oil leak in the pictures it shows it soaked the wireing harness, could that affect the o2 sensor and knock sensor? They both run in the harness.
 
#6 ·
I don't have a code reader atm and my local auto shops are closed is there a way to turn the cel off so i can see if it keeps off our sees more issues? I also was looking online for ecu reset procedures for my car but i can't find any, also the ecu doesn't have the led or screw to manual reset which is weird.
 
#7 · (Edited)
loosen and retighten your ecu grounds on the intake too. is there any leaks in the intake like on the acordian part. try the leak stop i seen that work wonders man. bars head gasket stop leak half a bottle. it might plug the tubes going into the throttle too which is not a bad thing imho. the screw with led next to it is on passenger side. if not unplug it for a day or wait til the parts store open. hard to diagnose stuff on the net. also DO NOT buy that cheap shit. get NTK or a scrap yard one is better than that off ebay. trust me youll be throwing away money. THERE IS NO ECU SCREW ON THE 2000 to 2002
 
#9 ·
no stop leak on oil will work man. i thought you meant coolant. oil leak stop wil just swell the seals but not metals or gaskets. forget the led on ecu you dont have it. you might not even have bad o2 either. it may be missing or running lean and ecu dont like the reading. like i said hard to diagnose on net.
 
#10 ·
Very true is hard to diagnose. Since there hasnt been a coolant leak in about 4 months what would cause just the heater circuit in the o2 to go out? and not just the o2 entirely bringing up more codes than just 1?

Would pictures be helpful? I can get any evidence you may need. Im a diy person and don't see having a dealer or mechanic work on a 17 yr old car lol
 
#11 ·
o2 volts reads would be best. but thats not happening. keeping that circuit bad or shorted long term could be bad. its ground all tied together. ecu sees bad results trys to compensate . get a different o2 from the yard or try a new 1. last cap n rotor replacement? cheap from rockauto . injector cleaner. the o2 is not heating up quick enough or at all to go into closed loop. like y2k said could of been water intrusion. mine was rusty as all shit and didnt throw a code just switched slow
 
#12 ·
Thanks for the info on this. I'll swing by my local junkyard tomorrow and pick up a o2 sensor, and I'll reset the cel and see if it comes back soon.

Just of more issue, i got my starter replaced and now there is a slight grind at startup. Could that be from low power steerg fluid or the actual starter not dissengaging fast enough and hitting the fly wheel?
 
#15 ·
The p0141 is the rear O2 sensor and could be screwing with the mileage. I had the same problem with a bad O2 on my 02' turbo car and it was screwing with the fuel tables, I am running without a rear O2 now and it runs so much better. If you don't want to buy a O2 right away just unplug it and do a mileage check. It will have a CEL that can't be reset but will run fine. Usual oil leaks I have to fix on 160k+ mile SR20's would be the distributor Oring, Valve cover gasket, front main seal, and oil filter housing orings.

For OBD scanners I use Torque android app and a China knockoff bluetooth OBDII adapter. My 2002 has trouble connecting to almost any OBDII scanner. Don't know if the 2000 models are better than the intenal map 01-02 ECU's. If so you just have to keep trying to connect until it finally works, then it is really slow to report feedback on sensors too. I'm guessing that it's just a weird Hitachi communication deal on them.
 
#16 ·
I will unplug the o2 sensor tmrw and see the difference, also for my oil leak I replaced the distributor oring and now I dont know where it is leaking from it looks like behind a rusty looking bracket behind the dizzy. I have pictures of the oil leaking pretty badly just in this spot.
https://imgur.com/a/oNGbL
Any chance someone could find a o2 sensor I may be looking for online just in case I cant find one in a Salvage yard near me?
 
#17 ·
Bosch # 15437 for one that you won't have to replace for a long time. The $25 - $35 dollar ebay units (also got s cheapo from rock auto that burned up too) I have tried last 1-2 months and burn up. I wouldn't suggest a used O2 since they are a wear item and really should be changed every 60-80k miles. If you watch your fueling on a scanner between a good OEM o2 sensor vs a old 100k mile one you can see the response difference. On a 2 bank engine (V6-V8) it's pretty cool to put one old sensor on one side and a new on the other to watch the trims real time. But I also understand you have a really high mileage car that you might not own much longer so you are trying to go as cheap as possible. Just be glad it isn't a California 2 bank engine with 6x O2's :)

OEM Bosch at rock auto $62.79 - Saw one on Ebay for $59.99 shipped.

http://www.rockauto.com/en/catalog/...60,exhaust+&+emission,oxygen+(o2)+sensor,5132
https://www.ebay.com/itm/NEW-GENUIN...ash=item1a3d70afb2:g:fusAAOSw4PxaOXHH&vxp=mtr

Edit - That leak can only be the valve cover gasket set or the distributor Oring.
 
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