Sensor Problems

T

tr3

Member
I'm new to this site, looking for a little help

Just bought my first Tacoma (2002 V6 4 Door) a few months ago, already having a couple issues.

A few weeks ago I got a P0141 code along with a P0420, I replaced the downstream 02 Sensor, ran it for about 100 miles, now the light intermittently comes on with a P1135 (Air/Fuel Ratio Sensor), P0420, P0420 p/d.

I've looked into this a little and seems that air leaks can set those sensors off. I've checked all around the cat and don't have any leaks, the only leaks I have are down by the muffler. Is it possible the leaks in the muffler are setting those off? Seems to be too far away from the sensors but I'm not overly familiar with tacomas.
 
I've said this once and I'll say it again. If you have a sensor in your incoming air supply (I call it a oxygen sensor) and you get code readings of any kind, the first thing you want to do is clean the oxygen sensor with a spray can of CRC electronics cleaner (or any good brand). Don't use brake cleaner, soap, whatever, you will just mess it up. Don't touch it (very delicate) and expensive.

Removing the housing and cleaning won't take more than 10 to 15 minutes.
If this is not the cause of your problem, at least it will run better when you fix the real problem.
I had a 1999 Tacoma that gave some ridiculous code readings, and this was the problem!
 
Hey I too have a 2002 Toyota Tacoma double cab 4x4 with the 3.4. I bought it late last winter with the check engine light on reading the P0420 code. It was a one owner truck with 175K, full documentation, great mods and was well under NADA book value.

Since it is not my daily driver I've not had to address it as a matter of utter necessity. I did, over the summer, buy two new Denso O2 sensors off of Amazon. They were reasonably priced and I thought I'd take a shot and see if it'd fix the issue. After a few attempts at wrenching the rear sensor off I gave up and took it a great exhaust shop in my area. They didn't even mess with trying to wrench it off as the sensor mount is trapped up against the frame and the nuts are locked on after 175K of weather! They cut out that section and welded a new mount! Unfortunately the check engine light came back on 100 miles later.

So now what? Well I've decided my Christmas present to myself and truck is a new Magnaflow OE front cat. I'm strongly considering just getting the rear one too. After looking through all of the documentation on the truck and determining they've never been replaced I'm sure it won't hurt at all.

Hopefully you'll be able to clean your connector ends and fix the issue!
 
So I cleaned the incoming air sensor really well, still have the same codes (P1135, P0420, P0420 p/d). Obviously to save as much $ as possible I want to avoid replacing the cat, but right now I don't know what else I can do
 
Any other ideas? I cleaned incoming air sensor, tested A/F sensor (tested good), replaced downstream o2 sensor, checked for any exhaust leaks (didn't see any), but I'm still getting P1135, P0420, P0420 p/d
 
Well p0420 code whipped! The two new oem magnaflow cats solved the problem. And not to mention one or both of the cats was clogged as I seem to have much more power now. Pretty sure my gas mileage is improved as well since the ecu is getting the right signals now. $650 parts and $60 labor from the exhaust shop. Merry Christmas to me... It was worth it.
 
I did the same; replaced both cats along with 02 and A/F sensors and have not had any problems. Also noticed a increase in power and mpg's.

Now what I've been told, correct me if I'm wrong, but the cats should almost never go and that there is usually a different underlying problem that should be addressed (bad exhaust valves in engine, fouled plugs, plug wires deteriorating...). Any experience or advice with this?
 
I have a 2003 Xtra cab and had the same problem with my light blinking on and off, had new exhaust and everything put on, to sum it up, what fixed mine was an ignition coil, it would just read bad sometimes an make the light flash sometimes, but I changed that and it hasn't been on since!
 
You must log in or register to reply here.
Back
Top