Check engine light during towing

[djskorch]

So bit of an odd issue.

This has happened twice both while towing.

Incident 1: Towing a 1500lb tent trailer on hwy. Floor it to pass semi. Check engine light comes on with no loss of power/hesitation etc. Code pulled 15 min later at autozone is P0133/ O2 sensor circuit slow response time. Reset code and never had issue again until...

Incident 2: around 1 year later (Towed a couple times between with no problem)

Towing a 3900lb load (2000lb trailer with 1900lbs of scrap/garbage from gpas shop)
Going up long steep hill to dump and check engine light comes on again. Finished load, took to shucks and get the same P0133 code. Reset it and has been fine since.

So why am I getting this? First time engine was N/A, second time supercharged.

Any ideas?

 

[HCurphy]

change the O2 sensor?

It's not getting your fuel ratios right, probably getting them close until you put it under heavy load. What kind of set-up do you have?(supercharger?)

 

[djskorch]

I would have thought that but the first time was only a few weeks after I bought the truck and the o2 sensor had been changed around 5000 miles before that so...

 

[HCurphy]

check the brand. Is it a bosch?

have you done any of the fuel upgrades that usually accompany a supercharger?

 

[djskorch]

Yes it is a Bosch. All I have done with adding the Supercharger is 2 step colder ngk plugs/93 octane gas and plugging the boost port to the FPR to raise fuel pressure under boost.

(Nobody jump on me about this. I have NO pinging at ALL. Even towing the trailer up the hills,on the freeway with the HG/L RPM NONE. Yes i will get the URD 7th kit when I have the cash just for good measure)

But I dont think the SC has anything to do with it since I got the same code a year ago when I was N/A.

 

[HCurphy]

It's possible the bosch sensor is giving you the issues.(Denso is preferred and OEM) LOTS of people here say the Runner/Tacoma just don't get along with them. Though, some people run bosch and don't have issues, it seems much more common that the bosch sensors cause problems. It's hard to say if thats the case for you...

This is a tough situation. I don't want to say trash that sensor and get a new one if it only gives you problems twice a year--but that may be the answer.

I guess i'll have to say I don't have and answer for you. Other then the above stated or just clear the code when it comes up(since it's so infrequent).

Good Luck To You.

 

[djskorch]

Thanks for your input HCurphy.

Any other ideas?