Check Engine Light/O2 sensor??

Hi, i'm new here... but i'm having a problem with my 1995.5 Toyota Tacoma 4x4.3.4 V6 3" Body lift with 33/12.50/15s and 267,000 miles on her! She gets me where i need to go. But lately ive noticed that when i start her up and wait a few minutes for it to slightly warm up, I leave my driveway and turn on my side road that leads to the main road and go to pick up some speed and it bogs down a little bit. So i let off the gas and hit it again and its fine.

Its been like this for about a month or so... Then today my check engine light came on. So i took it to Advance Auto and they said it was both Oxygen Sensors. And ive been noticing poor MPGs.

One problem is... I only see one RIGHT in front of the CAT, I dont see anything behind it, all the way back to the muffler. The guy told me there should be one on the exhaust manifold. Well i dont see it... I see a place for it. Theres a flat plate there but no sensor hooked to it ( I can post a pic if needed). But then that would technically make it 2 in FRONT of the CAT. so im confused.... But i didn't lay on the ground yet and look under, it might be on the far side of the exhaust, but i was thinking it would be on top like the other one is.

I dont have a lot of money, so it would take me a while to save up to buy anything. I think i can get the $60 it would cost for me to get 1 sensor. But is there anything else i should do?

THANKS FOR ALL HELP IN ADVANCE!!

 

The O2 sensors on my 2002(Three of them) are $160 and increasing with the price of platinum.

 

Geez!!! I can get mine for about 57 a piece.

 

the one behind the cat is about 6 inches behind the cat it points toward the driveshaft/ transfer case.

make sure your cat is not plugged up also.

 

Ok yeah... i wasn't sure if i wasn't looking in the right spot. I will get on the ground and look under it tomorrow. And i was just talking to my husband about popping a pipe through the cat lastnight, so thank you! =)

 

No problem glad to help. The front one will test your nerves not much room.

 

lol ok, thats not the greatest to hear because my husband doesnt have a lot of nerves lol. They run short...quickly!! But i think i will definitely talk to you if i have any questions =)

Do you think its more the cat than it would be the o2 sensors? I'm sure its the factory Cat... and i dont see why both sensors would go bad at the same time...unless it was the cat.

 

I have the same year as yours. I have around 238 on mine i think. I still have the cat and o2 when it came from the factory.

Have your husband try this with the O2 sensors. get some throttle body cleaner thats 02 Safe now and clean the sensors and try again before replacement. Alot of times carbon build up on the sensors keeps them from running the way they should.

 

ok will do... thanks again!

 

Cleaned the 02 sensors... and busted out the Cat... took off my K & N air filter to clean it, so im waiting for it to dry before i take the truck for a test drive... we will see if anything changes... =) *Fingers crossed*

 

Ok... took it for a test drive and its A LOT better!... Sounds a little funny...i guess cause there really isn't a Cat there anymore, but i have a lot more horsepower! When i used to floor it, it would get up to speed really slowly and then hit the rev limiter... it no longer hits it =) She can BREEEEAAATTHHHE

 

no codes? then its a good deal.

 

Well, it hasn't come up yet, i had the guy clear the code the other day when he told me it was the 02 sensors... it hasn't come back on yet, i just give it time lol. But i hope it wont, i hope it was that problem.

 

Me too! and for sure! I sure hope they dont though... i cant afford them right now, they dont look all burnt up or anything, they're slightly white and look ok.

 

Ok so my check engine light did come back on... GREAT.... so this time i actually got a print out of it....
Here is everything it says...
code P0420
Catalyst system efficiency below threshold-bank 1
Probable cause
-Air leak in ehaust before rear H02S
(eated oxygen sensor)-Bank 1
-AF sensor error
-Fuel System fault
-Faulty Catalytic converter

So now i have a whole list of things, and my gas milage still sucks... SO PLEASE HELP!!

Please keep in mind i busted out the Cat... Oh and i've also added SeaFoam so i'm hoping that will help some?

 

I have tried cleaning old 02 sensors before and it didnt work. The check engine light came back on. I ended up replacing the 02 sensor and it resolved the problem. That's something for you to consider. But if you do decide to replace the 02 sensor, use OEM Denso only. I bought an OEM Denso on ebay for about 45 bucks. First I went to Denso's web site and looked up the part number, then searched ebay for that part number.

Others on here can give their thoughts as well. In my case, it solved my problem.

 

OK thank you.

 

The reason why its throwing the "code P0420 Catalyst system efficiency below threshold-bank 1" is because you hollowed out your cat and its making the O2 sensor think that the cat isn't working correctly due to the increased flow. This has no affect on the efficiency/power of the truck because the second O2 sensor is just there for emissions monitoring. URD sells an O2 sensor simulator to get rid of the CEL if it bothers you.

 

I was thinking that thats all it was, but why do i have poor gas mileage along with it??