throttle and butterfly valve question

Sounds good. carbon buildup can play havoc with a computer's ability to self-manage itself.

 

sounds almost like my symptoms. i did get a MAF code after i bought my truck its a 97 2.7 tho. cleaned the MAF and no CEL ever again. replaced the TPS, cleaned the throttle body checked about everything and everything is ok. so maybe it is my MAF after all. let us know if things change again

 

Ok truck is still getting horrible gas milage. I have done the following clean maf and seafoamed they vacuum line just the other day. I bought a scanner and its says I'm not ready for emissions testing because " EGR system Incomplete and Secondary Air Incomplete". What are these and how do I fix it?

After some more searching around I dont have either one of those on the truck.

 

Here is some more info that may help its ib the links down the page some. http://www.tacomaworld.com/forum/te...-someone-know-how-read-these.html#post5689987

 

actual code numbers will help better.

 

There are no code numbers and there are no numbers stored in the computer.

I'm getting around 11 mpg right now.

 

Still better than Monte

 

I was getting 18 and 19 a little over a year ago.
Can an o2 sensor go bad and not throw a cel?

 

I'll be subscribing to this thread. I have a 03 pre runner trd with the 3.4, no 4 x 4' but I am running non stock tire size. (265 70 17 nitto terra grapplers, stock Toyota 2005-2011 rims plus spidertrax spacers all around) My average gas mileage is running about 15 mpg, city driving, frequent lights. Seems low to me? I'm assuming my tires are bringing me down a few mpg and my ultraguage isn't set up to compensate for tire size yet.

I cleaned my throttle body and maf sensor today, hoping i might see some improvement in mpg. Not throwing any codes either. And yes, when I manipulate that cable a little bit from under the hood, the butterfly didn't open for me either. I wondered about that too I have no unusual smells or any rpm drop off. My tail pipe is very clean. About 70,000 miles on the taco. I bought the taco a few months ago, have all service records and it was very regularly maintained. I'm thinking maybe I should have my mechanic do inspection/engine diagnostic during my next oil change.

I'll be curious to see what the op finds out.

 

I'm thinking about taking it to another dealer to see if they can find out what is wrong with it.