O2 sensor replaced and now truck runs bad

1999 Tacoma 4x4,3.4 V6, 160K miles

My CEL came on the other day and the code was P0135 which indicated a faulty O2 sensor. I bought the BOSCH universal sensor and installed it correctly. Then on my test drive to the filling station, the truck fell flat on its face and wouldn't rev up. I filled the tank (it was already half full) and limped home. It would accelerate after a long pause but climbing a hill or trying to hot rod, it would just fall flat on its face again. I shut the truck off and it would restart and idle like there was no issue. The truck never died anytime during this time.

Then the CEL came on again and so I decided to just unhook the sensor and see how it ran. Ran fine. Hooked it back up and it still ran fine. I went ahead and changed the filter since it's appeared to be a fuel delivery issue. I drove it all afternoon and it appeard to be fixed but this morning, I got about 2 miles down the road and it started to sputter again.

My question to the group is:
1. What is the best method to test fuel pump pressure? Is there a port on the fuel rail to test this? I've checked the forum for this procedure but haven't found anything.

2. This all happened after I bought the universal O2 sensor. As a matter of fact, it reared it's head on the test drive after installing it. Yes....I double checked the wiring with BOSCH and it is correct.

3. Are these trucks that finicky that you MUST use an OEM O2 sensor?

4. Would an O2 sensor cause these issues?

BTW.....It ran just fine with the CEL on before the new sensor.

I'm stumped because the problem is just too interminent to trace and it's too much of a coincidence that it happened immediately after I replaced the sensor. I've since had the code reset but I have a hunch that it won't take long before the CEL comes back on.

Thoughts?

 

I guess that will be my next move then. I talked to the guy at Advance Auto and he said that I can return it because someone there should have cautioned me about the universal one. He also said they have the OEM in stock.

98tacoma27....do you have personal experience with this issue? Not to offend but I value experience over common opinion.

I can understand the truck not liking a universal sensor but would that indeed make it run worse than a faulty OEM sensor?

Thanks

 

I read this thread, and I'm eager to know if a Bosh will make it run bad too. Thankfully I wasnt in a hurry when I bought mine, so I did some research before I bought one and knew to buy OEM due to complaints about Bosh in Toyota's.

Lumberwagon, check prices before you buy an OEM from Advance. I just bought an 02 sensor and all the auto chain stores were more expensive than buying online. I bought mine on line. Installed it yesterday-fingers crossed-no check engine light in 36 miles so far.

 

Bicklebok....

I know what you mean about prices, I checked at rockauto and they are definately cheaper, almost half price. My only concern is whether advance takes it back or just gives me credit for an OEM. Shit....it's only money! Right?

Luckily the TuRD is just a play truck for me and I still have my Ram to get me around. I'm just tired of 12 MPG in the big truck and the thought of 18-19 in my TuRD kinda gives me a chubby. I'll just have to wait and talk to them first and see what I can work out.

I'm interested too in finding out if a BOSCH will actually make it run worse from someones experience. I will certainly post my experience once this is all over. By "run worse" I mean giving the illusion that the fuel pump is taking a dump.

I had done what I thought was a fairly thorough search on here before I went with the BOSCH but the threads get soooo littered that I couldn't find anything with ease. Live N Learn

 

12 mpg? Ouch! My Tacoma is not a daily driver, and after I filled it up yesterday at 17mpg, it will never be! The only reason I filled it up yesterday was so I can check the mileage after I installed the new 02 sensor and other tune up items and see if mpg gets better.
Rain, cold, hot, I usually ride a motorcycle to work every day. And I mainly ride it just for gas mileage. I get between 39-42 mpg. I am not going to be a victim of high gas prices!

Apparantley, non OEM 02 sensors can even due damage to the ECM from what I read on another thread. Im sure someone else will chime in about this.

 

Thanks guys for the advice and comments. I'm definately going to persue an OEM sensor if nothing else, just to eliminate the possibility. Stay tuned for my results. With any luck, I'll have some good news/advice for everyone.

Yeah, 12 MPG sucks ass. Especially when I pull my tandom with my Mule on it. Takes it down to 9 MPG in a fat hurry. I sold the KLR for divorce money and it was getting 62 MPG but the highway scared the shart out of me anyway so I don't really miss it other than some city errands.

A couple of months ago my fuel bill topped 600.00 for the month. That's when I decided it was time for a minitruck. Any gains are better than nothing at all.

 

What's the latest?

 

Latest update:

Got the old sensor back out and took it to Advance. They wouldn't return it and replaced it with an OEM sensor from BOSCH for a bit of extra cash (my options were limited).

Got it installed and I'll be damned......still runs the same.

I plan on going back tonight and demanding a refund. I confirmed with the guy at the counter that the OBD II code readers are in fact accurate and he said it was considering I only have the 1 code (P0135). I would understand if I had multiple codes, leading me in the direction of a different failure but it's just the 1 code. I'm starting to get frustrated. I see on their site that they do offer a DENSO sensor so perhaps if the refund route doesn't work, they will exchange it for yet another one.

Sigh.......

I'm still waiting to see if anyone can tell me an effective method for checking fuel pressure. If I didn't know better, I would think it was a fuel pump but it's just too coincidental that it ran better before the new sensor and the symptoms started immediately after I installed it.

Keep the comments and advice coming guys, we're not out of the woods yet.

 

Thanks for the link. I don't have the special tools but I'm pretty creative so perhaps I can use those instructions as a guide and cobble something together for a test.

Still baffled about the sensor though. By the time this is done, I might just certify myself in O2 sensors. LOL

 

Same kinda thing happens with spark plugs dont it....like our engines not liking bosh plugs.

 

Youre a pretty sharp fella, but I have to ask. Did you save the old 02 sensor? If you did you could put it back on and see if it runs ok.

By the way, Im at 72 miles with my new Denso 02 downstream sensor, and no check engine light. I think that cured it. One things for sure,no amount of cleaning an old 02 sensor will get it working properly once it quits reading right. I tried!

 

I did save the old one but when I cut the pigtail off to use the "universal" one, I didn't leave anything to re-attach it on the old one....still think I'm a sharp fella? LOL (in my defense, the pigtail was only about 6 inches long so I needed everything I could get)

I think I'll just put the old one back in and unhooked and drive with the CEL on until I drum up the cash for a DENSO. Since I have another ride it's not that much trouble, just a damn hassle.

Pretty amazing how different manufacturers products can cause so many problems when they consider them "exact" replacements. You'd think that it would be regulated/tested first.

Another interesting thing worth mentioning is that although the CEL isn't on with the new "OEM" sensor, I think it's just a matter of time. The truck roars out of the driveway and within about half a mile to a mile, it starts fading fast. I tried to pull into traffic 2 times yesterday but I couldn't make it. Made my butthole pucker and had to back up both times til the coast was clear. Talk about embarrassing!!! I need to start wearing a disguise on these failed test drives. I know my neighbors think I'm a kook. I leave in the TuRD, come back 5 min later, switch trucks and leave again. Pretty much on a daily basis. It's really bad when I lay rubber thinking it's fixed and then limp back a few min. later. UGH....

Worst case scenario is that I'm just going to have to eat the cost of the sensor from Advance Auto and buy one on line. Perhaps they will at least give me store credit. But I must say, I can get one out and back in in under 5 min.

 

I still think your a fart smeller, uh smart feller. LOL Keep us posted!

 

Let me know if you decide to get the correct (Denso) one from Advance Auto. I have some codes that you might be able to use to save a few dollars.
​

 

OK....Took the second BOSCH back to Advance and told them I needed the DENSO brand. They wouldn't let me return it so I just got credit toward the DENSO. I figured that was my only option anyway so I complied. It will be in this afternoon. I'm kind of kicking myself for not thinking ahead on this one and getting one on line and taking advantage of the considerably lower price that all of you have told me about. I guess I have a tendency to want things NOW!

A little background on the "OEM BOSCH" that I had mentioned. As 98tacoma27 pointed out BOSCH is not OEM he is correct and I knew that. But I also have to admit that when I went in to get the OEM one and he handed me BOSCH, it didn't really dawn on me because I had looked at the connector and it was a Toyota connector and I just had a brain fart and went home with it. So I do stand corrected that the BOSCH isn't OEM. Not trying to make excuses, just admitting my oversight in the excitement that the even let me return the "universal" one.

So.....anyway, I'll be installing the DENSO sensor today but to be quite honest with you I'll be surprised if that really solves my problems. I hope it does though and we'll see.

Stay tuned fellas.........Once I resolve this issue, we're going to move on to DOOR CHECKS in another thread. If I take one more door hack to the back of the legs, they're coming off! The doors that is....not my legs.