: Just bought a cadillac, need some help

02-01-06, 11:13 PM
I just bought a cadillac 1994 fleetwoo, and I think I got ripped of. I was told it would get 17-15 mpg, but it is getting between 10-13. The check engine light keeps coming on. I have a code 32 and 55. Would this screw up gas mileage? What could cause such poor mileage? I looked up the codes, but they dont mean much to me. Does anybody have suggestions on which components to check. Thanks

02-02-06, 12:00 AM
32 is related to the EGR valve, and the 55 has to do with an oxygen sensor issue. Specifically, this is how they read out from a site on the net:

00-32...EGR open command did not change fuel mixture during off idle operation
00-55...ECM detected lean oxygen sensor during power enrichment mode

I understand the codes being kind of abstract, because I had the -32 EGR code register before just because there was a drastic change in the weather overnight, but I also ran into a code -32 with our '93 when it was spark knocking and the check engine light kept coming on, because the EGR was pretty much fried.

If there's a problem with either of those things, though, that could definately have something to do with your poor fuel mileage. I'd say to make sure neither the EGR or the O2 sensors are shot first, and then someone here can probably add more in terms of ideas....

And yes, you should be getting anywhere from the mid to high teens in the city to the lower to mid 20's on the highway.

02-02-06, 12:01 AM
Sorry, I meant 17-25 mpg

02-02-06, 07:14 AM
Well with an O2 sensor reading lean, the engine is going to try to correct for that by injecting more fuel. Change that O2 sensor and it should do fine.

02-02-06, 10:31 AM
17-25 is the EPA rating. You'll NEVER get that unless most of your driving is coasting down hills. :banghead:

My 1995 runs like a top and averages 16-18 in mixed driving, bad weeks are worse (15) and long trips are better (21-22).

It's a big heavy car, and the EPA tests are run with the car going 45MPH or some ridiclous figure like that! :wtf:

but fix your sensors and it will improve some.

02-02-06, 03:00 PM
How do I determine which o2 sensor is bad?

02-02-06, 09:03 PM
you only have one o2 sensor