O2 sensor faults

I have a 2008 CM Ted 5.7 with 275 K km. I am experiencing engine fault codes related to the O2 sensors. Local toyota dealer and two other shops said it was the right bank cat. So they changed the upstream cat and sensors on the rht side. No difference! Went 40 km engine fault code lit again. Reset it and it lit again after 50km. I bought a OBD II it tells me that both sides are sending fault codes. Any ideas would be helpful!

 

Everyone on here wants to know which specific CELs are being set and/or pending.

 

Your cat is probably gone.... if after the oxygen sensor replacement didn't resolve it, then the cat is gone... my car did the same, p0420, replaced the O2 sensor and it would come back after certain amount of miles....the miles kept decreasing after each reset until it wouldn't trigger a ready and I failed the smog test which led me to replacing the cat and it solved my issues..

 

The OBD says the 1 bank 1 sensor four times then it's 02 sensor 1 bank 2 sensor twice, then o2 - .. 2 bank 1 sensor.. i replaced the rht Passenger side cat 4 days ago and got two fails.My OBD didn't give the codes, like a regular code reader would.

 

Welcome

 

Bank 1 is the driver side.. if I'm not wrong... you replaced the wrong sensor.. again if I'm not mistaken. Bank 1 sensor 1 is driver side pre cat.

 

My phone went rogue and posted.... anyway take it to an auto store and use their obd2 system and grab codes..

 

I suppose replacing the upstream on the drivers ( left) might correct some of the faults... I'll find out tomorrow when that happens! It's $600 to find out. Hopefully that's the end of it.

 

The muffler shop has a code reader, I'll see if they confirm the codes before replacing the cat

 

Swap sensors between banks.

If the faults go to bank 2, it's a sensor issue.
If faults stay in bank 1 its wiring, bank specific, cat, etc.

 

The codes for bank 2 stopped and bank 1 started, so I'm thinking both upstream cats were toast..

 

I'll get them to try that first.. that's a good idea. Thanks!

 

Sounds more like a sensor from your response

 

Nice to hear from a fellow West coaster, thanks!

 

So in conclusion (I hope) the 1 bank cat was reduced to an expansion chamber! There was just the outer pipe, no insides. Replaced, so both upstream cats replaced. I trust this will be end if the engine service light being lit. Thanks for all suggestions, everything helps.

 

Welcome from LA (Lower Alabama)! Stick around after you get this figured out and this site will help you spend a lot more on your Tundra!

 

10+ extra hp for a straight pipe exhaust. Some people would call that a desirable feature.

Welcome.

 

LA I spent a month inbetween NOLA and Jackson. Quite different from what I'm used to. Had a great time.

 

Hadn't thought of straight exhaust pipes, for 10 up sounds like a good tip.. Thanks!

 

Welcome from the wet side of WA.

 

Thanks for the welcome! I live on east coast of Vancouver Island. West Coast weather is wet! But it beats ice and snow!