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Trying to get the O2 sensor off right now and don't seem to have anything to fit the nuts ... 11 mm too small and 12 mm is too big and nothing on the imperial side fits either, came on to see if I was missing something like some special wrench, so I guess it is vise grip time. I did get replacement nuts and studs just incase I needed them. Pretty remote here but at least there is civilization a few hours away. Will keep updated.
Wire brush the rust that's messed with the size so the penetrant can get through to the threads. When you get the vice grips on, get it as tight as you can, and take a hammer or deadblow and give some careful wacks to the handle. Try either direction of grip for the vice tool. Dont mean the rightey tightey lefty loosey concept.
Got the sensor out it was anything but cooperative. Ended up wire brushing it really good and after failing to move the nuts, went got some scape metal for a heat sheild and took propane torch and heated those nuts up really good. With the visegrips managed to get the nuts free. Cleaned up the port really good put new sensor in and anti-seize on the studs and snugged up new nuts.
Let it idle in driveway for 10 min no codes so I took out for a drive that was about 20 miles and still no codes.
I did take a picture of the sensor:
It's not as bad as I was expecting, I didn't clean it up was no real carbon build up or anything.
I think for right now going to do fuel consumption monitoring and see if I can get better mileage than before and see if the code comes back.
If all is good will put the cat back in to deal with the other code that came up saying the temp / pressure couldn't be determined.
Will keep everyone updated .... Thanks again for all the help!
Changing the front O2 sensor hasn't stopped it from coding: P0172 on Bank 1; today when I went out and drove it about 30 km. So I pulled all the plugs and took photos:
No excess fuel smell and the plugs were bone dry. When I did start the engine after I put the plugs back in for the first time ever it acted like it was flooded and ran rough until I increased the RPM and after a few seconds it cleared. It continued to act a little bit flooded afterwards when you increase the to high RPM and let the RPM's drop there was a tiny bit of flooding for like maybe a second and then it would run smooth. It did that for about a minute after several ups and downs it cleared. Turned the engine off and restarted as normal no signs of flooding. I did the tail pipe test for running rich and the pipe was pretty clean not suit and nothing coming off the tail pipe.
I did some reading on the P0172 code it has thrown after the new O2 sensor and I've not seen anyone successful post a resolution to that code. I have also gotten P0125 insufficient coolant temperature for closed looped fuel control just before replacing the sensor (hasn't come back yet); in my reading that is also related to a faulty O2 sensor. And then there was the code for the exhaust pressure after I took the catalytic converter off (it hasn't come back since I reset it).
From what I read P0172 can be MAF sensor and and injectors as well. The MAF looks clean to me but this is a new area for me. The injectors and injector rail on the donor motor came with it and were never taken off to the best of my knowledge. Giving the low mileage on the donor motor what are the odds it is an injector issue?
I've not replaced the rear O2 sensor its still original to best of my knowledge.
Anyone with ideas with where to look next?
Last edited by Noil; Oct 15, 2017 at 06:40 PM.
Reason: Fixed broken images from Photobucket
Thanks for the tip ... will clean the MAF tomorrow. Been doing a lot of reading and have learned quite a bit, didn't realize there is a difference between the 96 - 98 and 99 to 02 MAF. With the donor motor being in the later part of the 3rd generation is it possible that the 97 MAF is miss matched to what the motor is needing and expecting? Like the calibration of the MAF would be wrong for the newer motor.
Have found a guide to upgrading the airflow box and 99 - 02 sensor but the images are broken on which wires need to be re-pinned. If I can figure out which wires I need to re-pin to get the 99-02 MAF to work I would look at changing it out if cleaning fails to solve the issue.
Sounds plausible...my question is how soon did you or the previous owner run into these codes after the donor motor was put in?
Difference in model yrs in the same generation is amazing...like the engineers were trying all sorts of changes to improve the performance and/or adjust for whatever changes in company manufacturing, sourcing, you name it.
Plugs look fine alright. Rear o2 sensor monitors the cat's functioning. Dont know how it works if you decide to keep it straight-piped.
I put the donor motor in end of March through beginning of April of this year. Also replaced the cat and muffler at the same time. Didn't have a lot of time to test things out as I moved 3 weeks after getting the engine in back to Canada as my work visa was up. I noticed low RPM's and other small oddities on the move from NC but didn't think much on it as it didn't code anything. Mid August got the P172 code ... my brother and I thought ok maybe it is just a one off thing and reset the code. Coded again the end of August with P172 at which point I noticed the all familiar plug converter symptoms. So I got the cat removed in early September rest the code again and all was fine for a little until it coded again with P172 and now is doing it inconsistently when the motor seems to idle down going down hill or having to slow down by several miles per hour. Its kinda of hard to explain the exact conditions but I can tell its going to code there is a very minute hesitation almost like the motor stalls out but not quite; code comes up and it will run but seems to be hard on fuel until I reset the code again.
I have found the live diagnostic feature on the code reader I borrowed from my brother, so I am going to start keeping live logs and hopefully will catch it if it codes again after cleaning the MAF.
Have found the answer to my question on the wire pin out differences between 96-98 and 99-02; in the 96-98 it goes from air box side: black, brown, yellow, red and white and on the 99-02 from air box side it goes: brown, yellow, red, black and white.
Will give the sensor a good bath tomorrow and see where we go from there ... thanks for the help!
I cleaned the MAF sensor really good and once dried out I put it back inline with the air intake. I noticed the throttle body assemble was scored pretty good on the backside of the baffle, didn't have anything I was comfortable using to clean it on hand, will be awhile before I can get some cleaner. I don't think that is related to the issue but more of preventive maintenance thing. One thing I noticed immediately was that the cold start idle time was greatly decreased. Before cleaning the MAF the high idle on cold start would be about 2 minutes today after cleaning the MAF cold start high idle was about 40 seconds and then the motor started to idle down. No codes on startup went for about a 30 km drive and still didn't throw any codes, so I think I am at the wait and see phase again. I have started sourcing parts from regional auto recycling places to do the MAF upgrade mod just in case the cleaning doesn't fix the issue. Worse case is I will have extra parts on hand to use in the future.
Will update thread if it codes or if it cleaning has fixed it.
Oct 11, 2017 | 06:33 AM
