Heres the deal. I replaced the crank sensor and did not do a relearn. It was running so good I didn’t think I needed too. It ran really well around town and an occasional one hour trip. I had one code a Po303 random misfire code. I felt nothing. Ran real well.
Now today I left Georgia heading to Ohio. Truck ran very well until about 300 miles. Every time I’d go up a big hill the trans would kick down and start to loose power. The tach would go crazy!! Finally it just had no power at all so I pulled it over. I had my code scanner with me so I plugged it in and got 9 codes. From p0101 to egr to random misfire to p404, P1870,P0741P0335. Well you get my point. I cleared all the codes and the truck then ran real well again. Ran it like that for another 100 miles then it lost power again with a couple of the same codes. Cleared them and it ran well again. Almost to Ohio and I stopped again and cleared another couple codes and yes ran well all the way to my destination. It’s a 2001 ZR2 4.3. By the way I averaged 16 miles to the gallon!! Do you think a crank sensor relearn will fix this? Sounds to me like the crank sensor is messing with the computer. Please help. Thanks.