01 4.3l, 4wd 4door Jimmy, 170K on the clock.

Start it, idles fine, in gear light throttle it will stumble two times. Basically cut out, catch itself, and cut out, catch itself again then run fine. If its cold I see no problems with the gauges.

Sometimes it will do it when its up to operating temp, temp gauge drops off and once the needle drops to a point, stumble, needle starts to come back up, truck runs, needle drops and truck stumbles. Then its fine, happens fast, boom boom. Sometimes I can see the needle drop just a little and feel the power dropping off.

EGR is clean, new O2s, good plugs and distributor and it has a K&N cold induction kit. There is no SES light associated with it.

I do get a occasional MAF failure SES, resets and doesn't come back for a while.

Justin