Thanks. I'll run that test on the MAF when I get a chance. I'll try switching the coils as well. Pretty sure I'm gonna have a local shop troubleshoot it tho. I'll update.

After all that it was still an injector...So I am spending about $500 for something I already did. Pretty bummed. Mechanic was really cool and troubleshooted it for free until he could not find the problem. Compression was awesome and no coolant leaks which was good news. Determined there was no fuel going to #2 cylinder. Thought it might be the wiring to the injector but only way to find out would be to pull the plenum which was $255. It was already there so I let him as I need this resolved. Checked the #2 injector and it was like 3 ohms resistance. So after all that the coiling in that injector was failing all along and I put it right back in #2.

What are the chances I put the same injector in #2??? Crazy. He's gonna put a OE injector back in and is 100% sure this was the issue. Said the truck runs and sounds great otherwise. I'm out $500 plus what I already spent but as he said at least I have taken care of a lot of the issues that might come up anyway. Think I'm gonna pull the coils and return them though and maybe try to recoup some of my money.

Glad you fixed the issue. Maybe next time you can follow the advice of people who recommended you troubleshoot parts instead of randomly replacing things that are probably fine.

I'd agree with you if that's what I had done. I did troubleshoot as far as I could and everything pointed to the injectors. I pulled them and sent them to Witchhunter. Mechanic said the coil on the one injector was failing and even testing at Witchhunter may not have caught it as the resistance was fine when I checked it and when they checked it during their testing. Test data showed several injectors were below standard with respect to flow and pattern so it didn't hurt to have them all done in the long run. It'll only help with performance and mpg.

The wires and coil packs I did because the wires were original to the car and I wanted to avoid problems with the coil packs. The coil packs can be returned and were fairly cheap anyway. Nothing random about the way I did it. Only things I replaced were things that needed to be done regardless of the problem. Mechanic agreed and said he had to drive and troubleshoot for two days before he could figure it out as well. No random replacing on my end even though a lot of the advice given was to replace this or that. Problem solved now and I found a great mechanic who says my 4Runner is a sound car with no other issues he could find.

Joe,

I am glad that you figured out the problem, albeit it cost you $$$ out of pocket.

My uncle had a Ford Contour that had a cracked injector base that threw a code, but Ohmed out perfectly fine as well while running rough. It was only after turning off the car could one smell a little gas from the injector that helped us find the culprit.

At least though you know your 4runner is in great shape otherwise.

Wasn't trying to be a smartass, it just seemed like a very hit and miss approach to the issue, especially with all the stuff that you replaced hoping that they were the cause.
Sometimes these threads irritate me when people tell others to replace things without checking them simply because they are very easy to do. IE, your wires and coil packs.
But I will acknowledge the added confusion of your injectors being tested and ok'd once before. Those intermittent things are a biitch.

I get it and I agree that a lot of the people on here offer the replace this replace that advice but a lot of the stuff needed replacing except the coils which I could have troubleshooted first. The wires were original to the car so I'm glad I did those and the mechanic said that replacing those along with the other things I did like the PCV valve, cracked hoses and fuel filter probably got rid of the P0171 lean code and the other random misfire codes. That's what made it easier to diagnose and in the long run will make the car run better. The coil packs were hit and miss as I could have swapped them around but that only cost me $80 for all three so no biggie.

Overall I learned a lot, found a good local shop and now my 4Runner is in top shape.

True. Thanks for your help and advice I appreciate it. Frustrating but I learned a lot and now I can go back to loving my 4Runner and doing things I want to it.

I will be getting my first 2000 SR5 this weekend and it has the same issues that you first described. After reading all you went through I have a really good idea of what to look for, check, and how to go about it. Thanks all for the input and knowledge, it will not go to waste. Sounds like buying a code reader is def the way to go

Yeah the bluetooth one that I got from amazon is great. That with the Torque app make a great combo for diagnosing problems. Lot of great info on these forums and lot of help from everyone. Still running strong with no problems!

So your problem ended up being fuel injector? Were all of them replaced o just the bad one?

Got a bluedriver obd reader and it's been really helpful with diagnostics. For your specific cym;tom, I swapped out my maf for a "Returned" maf on amazon and that resolved the issue straight away and was easy to do.