Help! 1998 Tacoma V6 2WD Engine Light

Hey everyone! I'm new to this site and thought I'd try for some opinions on the Gremlins that have seem to take over my truck. At this point I'm losing my ass in costs. Engine light is on. Codes run by the mechanic, who is also a friend. Reads that both knock sensors are faulty. I bought the truck used from a not suprisingly bogus A-hole dealer that knew there was a problem. And of course would not back up the warranty.

My mechanic ran the codes after I tried passing smog. Smog guy suggested start there with knock sensors and cat converter. A starting point. Mech said ok, up to me. I said yes. He took apart and found knock sensors and gaskets were siliconed in, as well as gaskets. Also wire harness on those sensors were covered in electrical tape and he found one arcing. Changed upper and lower manifold gaskets, both knock sensors, and changed harness as well. He then reset codes. Not even 3 miles later light came on again, so I went back. Same codes.

So I left it with him again for a few days so he could again try to locate the problem. He started double checking wires, found a couple more arcing, fixed those, and double checked the timing belt which was off a degree. He corrected since he installed it. Found water pump leaking, fixed that. And replaced other belts as I requested.

Runs alot better, but still hesitates accelerating on freeway at just above 50mph. Feels like carb is clogged, but I know its not because it's injected. Any ideas out there in Toyotaland??? My guy is at the point where he feels the ECU needs to be replaced thinking there's a short. I got second opinion from Toyota Dealership. Says same codes, knock sensors both malfunctioning. They say computer is not bad or in need of updates. Just knock sensors.

 

I've changed plugs, wires, belts, timing belt, oil changes, trans service, water pump, air filter, alignment, knock sensors, gaskets upper/lower manifolds, valve cover gaskets, knock wire harness, and catalytic converter.

 

Hey thanks for answering my post. I have saved both files to give to him. He is leaning towards replacing ECU thinking there's still a short. Maybe now between knock harness and ECU. At this point he's tried everything else. He's tested ohms on both new knocks, tested fine. He didn't like all the tape on harness at knocks, so he changed. Also double checked other wires and strapped them down. Even checked the timing again cuz his employee said he had a weird inkling about the timing throwing everything off. Good call because it was off a notch. Most of this has been no charge mind you, or I'd be thinking he's taking me for a ride. Each time they've looked at it they have found stuff, and parts of it seems better, but still not up to par.

And of course my crazy butt started looking at vacuum hoses or whatever I can see, but I'm no mechanic. Even bought the book so I could maybe start changing other sensors I can find. Like MAF, fuel, O2 etc. It boggs bad when it tries to accelerate. Kind of like a clogged carb. Back in the day Dad would say put it in neutral and jump on the gas to blow it out lol, but I know thats not the case now with all the computer crap.

I'm concerned because I feel like my mechanic is giving up telling me to buy a new ECU. And he's had it several times checking over things and is a good guy. Also very hard to keep dumping it off with him because it's the only vehicle I have. What can I try to do on my own?

 

Now you're in the right place

 

how about your throttle body? have you had that cleaned. i had a 98 taco 4 cylinder with cel and that all it was.

 

Not yet Samsung. But now that I have the book, I'm willing to try several things on my own. Like cleaning MAF, O2 sensors upstream and down, maybe even throttle body. I also keep hearing things about blowing out carbon via vacuum hose using Seafoam. Putting part in gas, oil and motor direct. I may be just a CarpenterGirl, but I'm no idiot. I'm willing to try. My poor truck has 180k miles on it, so its bound to be gunked up. And if I understand correctly, if the previous owner had a code and ignored it, its now moved from the initial part possibly causing others to fail as well. It's just gonna be a chore to figure out how much it affected or what all to change.
Hell, maybe it would be easier/cheaper to just drop another engine into it.

I kinda want to find the problem though. I'm a little stubborn.