My Olds Bravada is getting really poor gas mileage around town all of a sudden. Like 13.8 mpg which is REALLY bad. I looked at the air filter and it looks OK although it hasn't been changed in a while. Also, the check engine light isn't coming on.
Does anyone have any ideas? I just went on a trip and was getting 19.4 mpg, which isn't too bad, although on flat highways, I can get around 21-22.
On Thu, 18 Jan 2007 13:45:54 +0000, WMB got out the hammer and chisel and etched in the wall:
A few things to check. You got the 4.3L V-6 with the CPI injector, right?
First, check the EGR valve. They've been known to cause issues.
Second, have your injectors checked. They can gum up and cause poor mileage/performance.
Third, or maybe first, start the truck and let it run a bit. Afterwards, go to your exhaust and take a whiff. If it smells like fuel, you've possibly got an O2 sensor problem.
Do a search on Chevy Blazer / GMC Jimmy issues. These are typically what you'll find. If you take care of them, the engine will last well over 100K miles. I sold my '95 in '01 with over 150K miles.