Can't be distracted by the light, must get the truck running right. Under the misery loves company heading, here is my entreaty to an 02 simulator site:

'I like your frank approach, if it not just rehearsed B.S. Your explanation of the way the check engine light comes on is valuable, but I need more information. The guys at the Toyota shop are not much help, rather they are more disposed to rubbing their hands in glee and salivating at my arrival.

Here is the deal. 2001 Tacoma 4X4, 4 door, 178,000 mi., Check engine light comes on, I turn around and drive to the dealership, (was actually on my way back from there, had put it in for tune up, oil change and front end alignment, as I was taking my wife to Vanderbilt for a kidney transplant that day), tech checked the code, said it was cat. converter code, also that I had a small leak on the water pump, and they could fix that when they replaced the timing belt, as it was time for that again. (Oh Joy!) He reset the code, told me to come back when we got back from Nashville, and off I went. By the time we got back from the hospital the light was on again, so I trotted down, dropped the 12 hundred for the timing belt. Talked about the cat. converter, (notice I say the, as in one at this point, cause none of them mentioned anything about two!!!) he had a buddy that changed them out with an aftermarket free flow that would fix me right up, for $244.00, guaranteed to meet all State, local and Federal requirments, and to pass any emmisons test, (um hum). Pop that puppy in and visit as it is being done, when the guy there says, "I can replace this back one, no problem, but I can not do a thing with the front one." (Omen here), PLUS, there is another code on when he clears the cat. one, throttle body position sensor, (or in English that equates to a $90.00 contribution to the cause), drive off the lot, light is still on. Back to Toyotaville, check on the (gag) price of the throttle body position sensor, have that replaced, they reset the code and I do not make it to the end of the service drive before the light was on again. I back up; ask them what I have to do to get this light off. Their only suggestion was to buy the OEM part, as the front cat. converter is attached immediately to an 02 sensor, which is in a curved pipe which joins to the exhaust with a flange, with three studs in it. You can not saws all it out and replace, cause the 02 sensor is so close to the cat., that there would be nothing to weld to. But for only $967.00 I can get their dealer part and put it on myself, that would save me the labor charge you understand.

One of the kids in the back suggested that I could take the front one off, run a piece of rebar through it, clean it out, ( Much, Much easier said than done), but here we go. Break over 1/2 drive, 2.5' cheater pipe, deep well 14mm socket, 1/2 impact wrench, 14 mm deep well impact socket, I am ready for battle. Get her up on the jack stands....one trip to Sears later, (that is not bad) a new set of stuck bolt removers, ( the first turn of the deep well 14mm socket rounded the nut ), I got the nuts going alright with the new nifty gadget, but they brought the studs out with them. Did I mention that the condensate drain from the A.C. is placed directly above the flange, so them buggers was welded tight. Try to find a metric tap and new metric studs at 7:30 at night in Podunk, TN. But the fates smiled, and the NAPA guys had got a shipment of an assortment of metric studs that day, first time ever for them to have them, and, they had taps to fit, not both bottom taps mind you, one of them was pointed. Why two you ask, well, the stud in the 02 sensor broke with the attempt to remove it, just under the nut, and as the housing is welded to the exhaust pipe, you can not get a pointed tap in far enough to clean out the threads. Why did all the studs just fubar the threads coming out??? Anyway, no stitches, just one bad blood blister from hitting my third finger on my left hand with a two pound shop hammer, AS I TRIED TO BEAT A DRIFT PIN THROUGH THE CONVERTER! I got it done, at 2:30 A.M., with it clamped in a vice, and a Forster bit on an extension in my half in. hammer drill. Fine layer of blue dust everywhere, and I have been hacking luggies ever since.

I can not believe I did not break a tap, with my hand all scrunched up by sheet metal as I chased the threads up on the flange. All the room in the world for a pointed tap there, but no, that was the bottom one. I ground the tip down on the other one and got a bolt to go in to replace the stud that broke, and NAPA did not have, get it all put together, take the truck off the stands, reset the code, (you can do that by pulling the EFR or some such fuse, letting it sit for a minute, then replacing. Fired it up, and the light was on within a mile. I pulled the negative ground, let it sit for 15 minutes, hooked back up, made it nearly to work before the LIGHT WAS ON! To boot, the added bonus of about 25 miles per tank less than I was getting with the clogged up converters.

Two codes you say? Is one for too much 02 in the exhaust and one for too little? Will you mileliminator work on my Toyota truck? Anything that can be done to regain my better gas milage?

Inscrutable, that's what they be, those sons and daughters of Nippon. This is probably a subtle clue about their next sneak attack...the Pearl Harbor of the Yankee wallet.

Sorry to hear of your oddessey, don't know anything that would help. I just bought my first FI vehicle in June last year, haven't looked under the hood yet.

Dan

Pres., TYHC

http://www.Gasoline.Alley

easy fix - put black tape over the check engine light

I agree with Butch, drive it till it pukes, give it back to Toyleta(preferably on fire) and buy an older Chevy. derf

their not check engine lights, their idiot lights.

If it bothers you that much put tape over it and drive

Worriedman, how is your wife doing?

Now moving on to your Tacoma, the first thing you should do is promise yourself not to go to a dealer for servicing unless you have to any more. I'm sorry but dealerships are the most expensive place to get a vehicle worked on and often aren't the most satisfying either. If you could start asking around and find a local garage that works on Toyotas and take your cars there from now on, I think you might get better help.

It is hard to diagnose stuff over the internet, and I've been away from wrench turning for a while so don't take this as gospel, but for starters did anyone check the O2 sensor? 178K is a bit of mileage and if the stud for it was rusted it sounds like it might be original. Also, the Coolant Temperature Sensor can be failing and giving a lower than actual temperature causing the engine to run rich. Also if it has a fuel pressure regulator did they check fuel pressures?

Also, if you are paying big $$ on this and are also able to do work on it yourself, by yourself an OBD2 scanner and then you can read the codes by yourself and reset the light when it goes off. Actually there are 2 different type of tools- one is a "code reader" which only reads the codes and possibly has a reset button for the light, and a "scanner" which can tell you most EVERYTHING that is going on in the engine. browse those 2 terms on the net and decide which you are most comfortable with. An interesting looking product is at autotap.com, but I haven't seen one in real life nor do I know if they can work on toyotas.

Also, there should be 2 O2 sensors on your Tacoma I believe? Just something else to check out.

Feel to post your continuing woes here

Mark,,you need to really shop the scanners,,I bought one and it gives the codes,,but no book to decypher,,clay

The last time I had to fix a cat converter, it turned out to be just an empty mag problem. So I just jerked out the old one,stuck in a new one and dropped the bolt. Working fine again.

Mark,
We just got in from Vanderbilt about an hour ago. (Four month check up). Pretty sure we sat through a tornado just past the Buffalo River, interesting trip. Truck is sand blasted with pine limbs and hail, windshield is cracked in about 15 places form the hail, all in all an interesting fifteen minutes. She is doing great in regards to the kidney, still NO sign of rejection, creatine (sp.) level at .9. She does have a blockage in her jugular vein from all the tubes they put in for dialysis and surgery. They are starting with aspirin therapy, then on to cumaden if required, or surgical removal, but these are all problems that can be dealt with. They cut her prednisone down to 7.5 mg. daily, and that is really good. Thanks for asking.

I replaced two 02 sensors last year, plus I had one of the guys check them with the diagnostic computer; they are all still good according to the machine. I unhooked the neg. ground again and left it off for 20 minutes before getting in and driving hard to Nashville. Actually got 340 miles on the first tank, which is 40 over average. One of the guys told me that the computer needs to reset when the air flow is changed, I had tried this a couple of times before, but that was dinking around in town, and today was hard interstate driving. The light came back on about the Tennessee River on the way up this morning, but the truck actually ran better and got over average mileage. I will have the Coolant Temperature Sensor checked out to rule that out. Thanks for the tips, I learn more stuff on here!!

I could probably do all the work, but my problem is time. I have a fair assortment of tools, added to with each new venture. As it is, with my truck, the wife's car, two daughters with cars, I do well to keep the oil changed and the tires plugged, and somebody always needs a brake job. It is all I can do to put in my 60 a week for the slave drivers I work for, try to keep the pernicious pussies at bay on my property, and deer hunt a little.

worriedman, if your truck has an O2 sensor in front of and behind the cat converter hollowing out the cat will only cause the light to stay on. The reason for the downstream O2 sensor is to keep tabs on the converter. Prolly get a P0420 DTC now. Heres what the theory of it anyway: The ECM observes the waveform of the heated oxygen sensor located behind the catalyst to determine whether the catalyst performance has deteriorated. If the catalyst functions normally, the waveform of the heated oxygen sensor located behind the catalyst switches back and forth between rich and lean much more slowly. When the waveform of the heated oxygen sensor located behind the catalyst alternates flatteringly between rich and lean, it indicates the catalyst performance has deteriorated. Clear as mud now? PM me when you get some specific code numbers and I'll see if I can get you some more info.

Laner, the code I was getting was P0420. Now have a simulator in place, (only one small razor cut during installation, not bad for me!), no more annoying check engine light. Been in place for a couple of days now.

Mark, checked out the Coolant Temperature Sensor, it appears to be within specs and functioning. Did check the function of both 02 sensors, both are working fine.

Have a run to the parental units (both) today, will see what the milage is with the light off.