Problem driving up hills

[nitrorc]

I own a '98 Chevy Astro Van LS v6. This thing has been in and out of the shop so many times I lost count. First the thing started shifting out of first gear really hard. It seemed like the entire rear end dropped. So I take into the dealer and they replace some part in the transmission. Now while driving up hills the thing tends to climb alright, just until you get to mid point. At this time the Check Engine Light Goes on and the car starts to shift into lower gears. I took it back to the dealer and they can't seem to find the problem. The van has about 116k and I am not sure what else to try. If anyone has any ideas please let me know..

Done so far:

Tune up replaced cap, rotor, wires, and all plugs.
Replaced that bad part in transmission.
Replaced water and ac belt.
Fuel injectors got cleaned out.
Rear seal on axle replaced.

Thanks...

[nitrorc]

I just replaced the catalytic convertor and car runs better, but service engine light comes on now. How do I read this, what type of tool do I need. Can I purchase one?

[3ForFred]

I just had the cats changed on my '01 Astro too. I was having the same problem with no guts uphill, but, it runs much better now.

Driving around later that day, the van threw a code again. I took it to Autozone and they will let you borrow there scanner, either with a deposit or leave your license and use it in the parking lot. Mine threw a Mass Air Flow out of range code and a random misfire code. I think I'm looking at new O2 sensors for the misfire, but I'll have a friend of mine with a Snapon scanner verify the mass air flow.

I have found not to trust the first result. I have had mine scanned several times from the dealer to a friend and now Autozone and they all seem to come up with something different. I'm not sure exactly what this means, but, the common code is Mass Air Flow and Random Misfire. If anyone out there has an answer for 'Random Cylinder Misfire' other than 'it could be anything', could you please let me know?

[rdemarais]

My tranny had a similar problem. As I would drive up hill it's make a heck of a cluck sound, downshift and the shudder would shake the while van. I took it to a local transmission shop that offered to replace the torque converter for $350. I passed and just kept messing with it. After considerable researh on the net I replace the throttle position sensor located on the passenger side of the throttle shaft. Two bolts and a plug-connection and I was done. Save me about $330. Fixed my problem too...

[CD Smalley]

I'd really suggest you guys spend the $$$ and buy a factory service manual. It will provide the answers you are looking for.