Exhaust leak, poor gas mileage

[RadicalTactical]

Need some advice.

I bought my 05 v6 in February with 130k on it. It's been a solid 17.9 mpg around town for the first month I had it, then I got ear ended. I heard an exhaust leak, which insurance fixed. New factory exhaust from cat back. Picked it up, over the last 3 weeks I've been hearing a slight exhaust leak, usually half throttle under load, not reving in the driveway. My gas has gon to a stellar 14.5 mpg, according to the dash.

Took it back, they did some tests, and said they can't find the leak. I've read about the leak near the manifold, but they claim they did a test and found nothing.

I've read the leak can contribute to lower mpg. How true is that in our 4runners? Anyone had a similar experience?

 

[RadicalTactical]

Since my last post, I've computed gas mileage using the trip odometer and gallons method. I am getting 11.75 mpg:faint: of course that does not include computing for the 285 tire I am running. Dash says 13.5.

Alao since my last post I took the runner to Toyota dealer and they conducted a diagnostic and said there is nothing wrong.

When the back window is down, I does smell like it runs rich. How can this be adjusted?

I'm stumped as to why I am losing mpg. No CEL, no hesitation on acceleration, runs smooth.

Any ideas?

I've had big plans for this, but I'm slowly losing interest. I chose the v6 due to the better gas mileage for heading to my hunting lease 180 miles away. I can't deal with 11-12 mpg.

 

[progress4m]

If you calculated the real mileage (accounting the upsized tires) your gas mileage is actually at least 12.7 mpg..
Possibly even higher if look for the actual size of the particular tires you have… it is still low, even for 100% city driving… but if you do not see any issues with your truck (no CEL, maintenance is done, etc.) considering lift, heavy\oversized AT tires and V6 (which probably struggles with extra load and being out of the power band) it is possibly as good as it gets…

The only other thing I would recommend to look at closer is O2 sensors, there are some reports when bad O2 sensor would cause issues like low gas mileage without CEL code.

You have mentioned you bought V6 for gas mileage… but once you start mod the truck (lift, tires, etc. ) your mpg (especially with V6) will go down drastically…
I would venture to say that 4Runner with V8 will have better mpg vs. V6 with the same mods… and it could be significantly better…


Good luck!

 

[RadicalTactical]

Thanks!! I was contemplating the 02 sensors. I'll have that checked out.

 

[themuffinman619]

Have you checked some of the easier things to check. Dirty air filter, MAF sensor?

 

[earthrealm]

i have several small holes on my exhaust..rust spots.......never bothered about it, but now am wondering if it has any serious issue on my mpg...i usually get 17 to 21mpg highway...and abt 12mpg city...my lieo meter is at 14.3mpg now

 

[progress4m]

Thanks!! I was contemplating the 02 sensors. I'll have that checked out.

Forgot to mentioned, I would also checked the brake calipers and made sure they are stuck creating an extra drag (based on reports from this site, 4Runner’s calipers are known to do that);

 

[RadicalTactical]

Have you checked some of the easier things to check. Dirty air filter, MAF sensor?

This was done by a mechanic after I bought it, as well as the synthetic oil.

 

[RadicalTactical]

Forgot to mentioned, I would also checked the brake calipers and made sure they are stuck creating an extra drag (based on reports from this site, 4Runner’s calipers are known to do that);

I read that as well and I asked the shop that put the lift and tires on to check that. I should probably check that myself to be sure.

 

[wnelax04sr5]

02 sensors would be my guess as to part of the issue if the poor mpg is unrelated to any other outside sources like tire size and your right foot. if a bad sensor is sending too much or not enough fuel your mpg will suffer