I have a 1999 1500 4x4 with the 5.9. They truck has 109000 miles and has had a rough life hauling and towing. The check engine light used to stay on constantly with an 02 sensor reading, and hasnt been on for the past couple of months after i put a 02 simulator in it. Last night the check engine light came back on, and i didnt think much about it. This morning when i started the truck it seemed like i had to keep it to the floor to get the truck to move. I let the truck get to normal operating temp and drove it about a mile down the road. When i put the truck in drive i have to hold it at 1200-1300 rpms to get it to move. Reverse is normal, no problems what so ever. Once you get the truck moving, it shifts out fine, but it seems like I am pulling a huge load with it ie no power, huge strain on the motor. I put it in neutral on a hill and it rolls fine, so the brakes arent locked up. Any suggestions? Im going to put a transmission filter in it in the am and hope that works!

 

I topped it off with TA fluid once it got up to temp

 

take the simulator off and plug your 02 back in, I had a sim ***** up my tranny. Use the non-fouler method to eliminate the CEL.

 

Check fluid in neutral. Get an inaccurate reading in park.

What code are you getting now?

Is the trans slipping? Or is the engine just a dog?

 

I filled and checked the transmission fluid in neutral. The engine is fine, but i havent got to check the code yet, im going to try to get that checked out tonight. Its been a great truck dont get me wrong, but it has always been a very rough shifting truck, and it has always seemed like 4th gear is a little tall for the truck... it winds itself out way up in the rpm range in 3rd gear before it will shift put to 4th even under normal driving conditions... may be time to finally get rid of a dog transmission!!

 

I will go ahead and unplug the sim tonight as well, right after i got the truck the catalitic converter (spelling??) got stopped up and i wound up having to punch a hole in it just to get home.. i welded the cat back up and then installed the sim... told u guys the truck was a beater haha!