Hey guys, i am having some high fuel trims on my 03 V6 6spd, that have me stumped..

I know by the "book" they are not out of range, but they are high enough for me to start trying to figure out why, the car is still running great, although MPG's are starting to suffer. Currently no CEL or pending codes.
STFT is running around +15 to +20 at idle and +10 to +15 at highway speeds. LTFT is running close to +7 to +9 at all times, bank 2 runs about 2-4% higher than bank 1. If i leave it idling for a few minutes the LTFT will creep up a precent or two.
To date i have replaced both upstream 02 sensors, PCV Valve, MAP Sensor and replaced the air boot (Mine had a crack).
New plugs installed about 3000 miles ago (denso iridium's)
I put in a used fuel pump last night that had 28k on it, and that didn't change anything..
I have checked for vacuum leaks but haven't had any luck in finding one. Is there any common vacuum leaks these cars can have?
I am at 105k Miles and have not done a valve adjustment yet, i am planning on doing one this weekend due to the mileage.. Could that be the cause of the high trim #'s?
Is there any other things i should be checking?

Thanks!

03 Accord V6 6Spd.
Comp-tech Cat Back exhaust
HFP Package

 

Use your scanner to graph the calculated load,rpm, vehicle speed and MAF grams per second@ idle,cruise and WOT.


Post the results for interpretation.

 

Thanks for the reply; I am using a scan gauge 2 so it don't have graphing capabilities. This car does not have a maf, only a map sensor

 

Unfortunate. Either take it to a shop,or continue with your internet search for the answer.


Better look again.....

 

The gen7 03-07 v6's do not have the MAF sensor
The gen7 i4 03 and a few early 04's don't have the MAF sensor either ...
From late 04-07 all i4's have the MAF

Then from 08 forward all cars came with MAF regardless of I4 of V6

If memory serves I think all California equipped cars came with the MAF regardless of year due to tighter emissions.

 

Not exactly.....

This is correct. Since I do not know if you have an SULEV, I asked you to look again. Some people know their cars very well,others.....not so much.



Either way,sorry I could not help you.
Good luck.

 

Thanks man I appreciate it.
Do you think a leaking egr could cause this? Or would that drive it to a rich condition?

 

Yes in addition to the valves being too tight. (both are pretty common) But typically if the EGR is leaking enough to effect trims,it will also be causing a misfire....

 

Did you fix the problem? I'm having the same issue

 

Check the vacuum line to the front engine mount. The engine mount has a vacuum driven damper . Mine was leaking at 150 k.

 

By the way a scanner with graphing capabilities is maybe $100 ? It might save you a large repair bill some day.

 

I had the same problem for my 04 accord v6 was the pre cats at the exhaust manifold were plugged up, do you have engine stubble when you go down a big hill?