RPM surge? 2003 H2

[etmyers]

I am having the same issue on my 06 H2. I had the garage clean the throttle body and it went away for a week or so. I also averaged a little more than 2mpg better. Since then the surging comes and goes. I also have went down about 1mpg less but still averaging over 1 mpg better than before the throttle body cleaning.

[charles06]

I'm still getting the surging. Still happening around 48 mph. I can literraly see my tach jump 2-3 times, then stop. Only happens when I first take the truck out.

[madmike]

My trans started slipping. Pulled the pan and found lots of metal powder around the magnet and in my filter. Changed out the fluid with no results. I think my clutch plates are fried!

[MrIgor]

i been fighting with this problem for last 6 month 03 H2.

I replaced 2 transmission (rebuilt units) mine was NOT a core. I have replaced maf, map etc... Nothing.

Only interesting thing I found; if I plug the truck and drive into a obd reader, the O2 sensors are going crazy and it shows it never goes past 3rd gear, but i was doing 65MPH at 2600RPM???? I think it is a wiring OR PCM problem.

[MrIgor]

Update: i checked all wires going to transmission. All perfect.

Interesting thing: I put it 92 octane gas into the truck, and it runs almost perfect. the timing will get changed to higher octane gas. Now question is now what??