Stumped at the moment

My 03 is experiencing loss of power when I have to climb hills. The following maintence has been done recently.

11/08 - Transmission fluid & filter change
01/09 = Replaced oil sending unit
02/09 - Replaced LIM, UIM, & valve cover gaskets. Also replaced spark plugs and fuel filter.
03/09 - Replaced air filter
04/09 - Replaced spark plug wires & ignition coil packs. Also replaced serpentine belt & belt tensioner.

The only regular maintenance that is overdue is replacement of O2 sensors. The car has 144,300 miles on it. Replacement of LIM gasket % oil sending unit took care of leaks. A couple of friends have suggested possibly the catalytic converter. The SES light is not on. The only time it was on was right before the replacement of the gaskets and has not been on since. Appreciate any help or suggestions you all may have.

what is the sea level of the hills?

every 1000 feet above sea level you will loose 3% of your engine's power since the air is less denser as you go up and therefore AF ratio will be affected.

Most are around 1000 ft but up toward wher my stepdaughter and & her family live its around 2000-2500 ft. I understand that you lose some but this is more than what would be considered normal.

I think these newr models arent affected by altitude to much.
Thier are sensors(Altimeter/Barometer?) that keep it in the right air fuel mix.

Thier were issues with the 2003 Converters. Id get that tested.

Was it doing anything else out of the ordinary ?
And was it doing this before the trans fluid/filter change, or jsut recently ?

It was doing it before trans fluid/filter change. Gas mileage is down by 20% also.

Still has the loss of power and hesitation when accelerating. gas mileage is off by about 25% now. Most of the responses I have received on here as well as from friends & family point toward the converter. I wish for once the SES light would come on and tell me that (converter). It's kind of aggravating when you know you have a problem but can't pinpoint it 100% and SES light won't come on. The only time it came on was about a month ago for a EGR-related issue ( hasn't been back on since).

Don't count on getting a SES light for the converter. My converter was plugged to the point that the car would barely start and I never even got a SES light. I would get the O2 sensor readings thats how it was determined that mine was bad.

the hill probablyy has nothing to do with it. if your on flat and mash on the peddle, it will do the same thing.
the converter sounds like a good guess.i mean , its not a huge job, so i would try that.

Does it matter as far as the brand? Everyone in my area carries Walker except for Autozone, which carries Magnaflow.

Honestly go with the one that has the longer warranty on it. You should be fine with magnaflow though. If you put a cheap converter in it will just go bad in a matter of months again.

Ok thanks. I did notice that the magnaflow at AZ had a 5 yr warranty.

Let us know if converter got it fixed.....

That is on my to do list as soon as I can get the $.

or you can try straight pipe in between when you remove the cat just for the test.

Haven't got the converter fixed yet but replaced my front O2 sensor about a month ago. Gas mileage went from 22-23 mpg to 27-28 mpg. Also cleaned my MAF sensor earlier this week and car accerlerates a lot smoother. Didn't look dirty but went ahead and cleaned it since I went to the trouble of removing it to check. Used CRC MAF Cleaner.

I'd wait and see how it does before dishing out the ca$h for a converter. :grinyes:

Could have just been the wires, egr, amd O2 sensor causing the issues. If nothing else the increase in MPG was worth replacing those components IMO. :D

On the MAF, I usualy clean mine every 2-3 months. Keeps the metering levels more steady, and more accurate. :2cents:

There is still a lack of power going up steeper hills but I can live with that for the moment. Just glad to get some MPG back plus the smoother acceleration. Also by cleaning the MAF I've noticed the RPM's don't bounce around, more steady.