Transmission or yet another sensor?

I have a 2000 Isuzu Trooper. The CEL came on while exiting the highway (only about a 15 minute drive) and almost stalled. It continued to to this for a day or two. Had codes read...EGR flow insufficient & EGR valve stuck closed? The light has since gone off and it had been driving fine. Now light is back on but when starting off from a complete stop slams or bumps into gear (it is an automatic) either from 1st to 2nd or 2nd to 3rd. Also, when coming to a stop it slams or bumps as well. When driving in higher gears it just doesn't have the power it used to. Could this all be related to the EGR prob.? Another thing I've noticed is the smell of burning anti-freeze when turning off car. I have noticed a few small spots on the driveway but had it pressure tested and told it had no leaks. I can't get out to have the codes read today so if anyone has any suggestions on these probs. I would really appreciate it.
Thanks,

Chris

well start with getting the codes read.
but you already know you have to do the egr, so do that first. look at FAQ1
http://isuzufaq.ibctech.ca/#faq1 just because the cel goes out doesn't mean the problem is gone. and don't forget to clear the codes once they have been read so you are not dealing with old data.

the power loss could be the egr.
the trans *could* (but not necessarily) be the result of poor running because that affects the electronics. your best bet is do the egr and then let's see.

there are a number of things the harsh shifting could be including the automatic transmission mode switch also called the gear selector mode sensor. it's external to the trans and not a big deal to fix or maybe even clean if you do the work yourself. but...egr first.

the coolant smell. you got to just look and feel all those hoses, and look under the common chamber between the two heads for telltale green -- there's an o-ring seal that can go. check the hoses at the rear of the engine that go into the firewall; they go to the heater. check the heater core inside, look for wet carpening especially on the passenger side. locate the spots on the driveway while the truck is still parked over them and see where they are coming from, that will go a long way to narrowing the choices down.

//bc

I had the EGR valve replaced as well as the serpentine belt (they said it was badly cracked). The dealership that used to sell Isuzus in our area dropped Isuzu but said they would still be able to service them. Apparently they don't have all of the diagnostics that they used to. After they fixed the EGR and reset the CEL it came back on while driving home and started the strange shifting or jerking thing so I took it back and they came up with the following...
Code P0106 MAP Circuit range performance not present, Torque on demand code 16 not present, front wheel speed sensor output off; code 21 TPS out of range. I'm copying this from the invoice they gave me. They couldn't tell me what they meant. The serviceman described it as "jerking" not slamming into gear as I described it. He said it could be the start of a transmission problem. I'm not sure what move to make next. It doesn't do it all of the time - I warm it up for about 10 minutes in the morning before driving it and it usually doesn't do it unless I've been driving it for a while. Somtimes it only does it the 2nd time I start it up. It's very erratic. Now I've notice it more when I'm going down hill without accelarating.
Any suggestions would be greatly appreciated.

-Chris

could be an electrical issue and the alt is starting to get weak.

How many miles do you have on the truck?

It just turned 90,000. Is there a way to test the alternator? Should I bite the bullet and take it to the Isuzu dealer 40 miles away?

90 is that that bad for your alt.

The proper way to test your alt is to have it load tested (which I think means it needs to come out of the truck).

are you the original owner?

We are not. We bought it at 62,000 miles. It seems like everything started going wrong when the place we bought it from did a tune up (2 years after we bought it) and put bosch plugs in it. I learned from this forum about the Denso so they switched them out. After that the CEL kept coming on and we've had the following replaced: camshaft sensor, accelerator pedal position sensor, upper engine cleaning with a new pcv valve, intake manifold gasket replaced, new egr valve & serpentine belt. The CEL always seems to be on. I don't mind paying to have it fixed but if it could possibly be the transmission I think I need to cut my losses.

Just wanted to post an update in case anyone else is having the same hard shifting problem. I have been having this problem for well over a year and have had several mechanics look at it. Of course it never performed that way for them and there were never any codes that could possibly relate to hard shifting. I had a new EGR valve installed as well as the intakes cleaned and a new PCV valve put in. I still got the P0106 code after having all of this done and still had the hard shifting. I was told my transmission was going out by the dealer that used to service Isuzus in my area. WRONG. I ended up taking it to the nearest Isuzu dealer 40 miles away, they put a new MAP (Manifold Air Presser) sensor in it and corrected all of the pressure readings (they didn't even charge me for the sensor & they washed my car) and all of my hard shifting problems have disappeared and it's running great, which it hasn't done in a long time. Hopefully this will help someone out there having the same problem.