Ode to an O-ring, and Oh, the P0125

No urgent question, just my most recent obstacle to overcome. Long story if you're bored.

This began with a wrecked car I was fixing. Was getting misfire codes, so I swapped over a couple of known-good injectors from one of my other cars. Since then, I've spent $100 on o-rings trying to get the darn injectors sealed.

What a PITA. Over and over, i'd install a new o-ring, carefully insert the injector into the fuel rail, turning it back and forth to help the o-ring slip inside. Over and over, it leaked, and after pulling it out, I'd find one edge got smashed ruining the o-ring. Dang o-rings at $8 ea, and of course, not any of the standard sizes in the o-ring kit I have. Hundreds of o-rings, none this size.

Finally got both cars sealed up and have been driving my daily car again without problems - until this week. The car threw a P0171 with random misfires on 3 and 4. I cleaned the MAF and throttle body with no difference (maybe needed to drive it longer? I just cleared codes, started it in the driveway, and they came back). So, figured I'd swap the injectors around to see if the codes followed them. That was a mistake. I was back in o-ring hell.

$50 more for o-rings and finally got them all sealed up again on the last o-ring I had. The original codes were gone, and it was idling smoothly. but it was now throwing a P0125 code and 130/133 codes about ox sensors, and smoke was pouring out the exhaust. Not good.

Went inside and researched those codes and decided to take a test drive to see if the thermostat was opening and whether the smoke would go away. All went good for a couple of miles, and the smoke had dissipated to almost nothing. As I pulled in the driveway however, the CEL went off again. Ox codes gone but still the 125 and now the random misfires again.

Researched some more - had plenty of coolant, car wasn't overheating, ECT acting normal - I could see the temps build up to 185 them drop a few degree when the thermostat opened, and then settle back in at 185. This happened at my brother's house and I wanted to get home where I had spare parts/tools, so researched some more to decide whether that 0125 was safe to drive 50 milles. Decided to take one more test drive because the car seemed to be driving just fine; I wasn't feeling any misfires.

Cleared codes, the car ran great, so I drove home, checking the codes several times along the way and monitoring my temps. Codes never came back and now the car runs great.

So, I wonder what that was all about. Ultimately, I did nothing except pull some injectors and put them back in. I'm pretty sure all the smoke was just raw fuel that got into the cylinders when I pulled the injectors over and over, or maybe a little oil, which I finally used to lubricate the o-rings when gas wasn't working.

And, I got these latest o-rings at O'Reilly's, and they seemed to be just a little looser on the injector, which allowed them to keep catching on the lip to get smashed. Could also be that they just stretch out of shape more easily, and got bigger when I pulled them to install. I know you're not supposed to roll them on, but they were so small it was hard not too. Used a pick on the last two efforts, and maybe that's why they went in finally, that and the oil.

probably wouldn't have had those problems if I had removed the fuel rail as the service manual instructs. I've always been able to just take the two easy bolts out and squeeze the #4 injector under by lifting the other end of the rail. But, that pressures the o-ring a little and makes them harder to line up correctly. Not perfect, but easier than removing the rail.

I'm still puzzled as to why I got the p0151 to begin with. I expect the raw fuel messed with the ox sensors to throw the 0125; but I don't know what triggered the 0151.

 

Yeah, me and my bro were saying the same thing - never had problems pulling injectors and just pushing them back in. I went to o-ring websites after the first struggle - there are soooo many different kinds, and I didn't have specs on the ones for this car. I noticed that the O'Reilly's computer showed the specs on their page for that part (Standard Ignition Part# SK-57), so I may go look it up and order a couple of dozen. I can't think that $8 price is just the o-ring - it does include the rubber bottom gasket, but those don't mess up much. The dealer gets $8 each for the o-ring and for the gasket.

 

Price is definitely based on customer need, and not cost. The packaging cost more than the o-ring.