Have a 1999 chev suburban 350. It shakes violently when going up hill. Sometimes, the check engine light comes on. Chev dealer said it needed fuel system cleaned. They did but no good. Have changed: plug wires, plugs, fuel filter, dist. cap/rotor, PCV, air filter, gas cap and distributor.

Also, can I get the SES codes or is this an ODB2 type?

Thanks.

Did ypu figure out your problem? I have the same one, seems common. Any reply would be appreciated.

I had a similar problem with failure codes P300 & P305. The cause turned out to be a bad fuel injector on the #5 cylinder. Check first for contaminated gas. It can foul an injector and #5 seems to be most sensitve. Try injector cleaner in a new tank full of gas for a week, if that doesn't work you may have to identify the bad injector and replace it.