95 Suburban 5.7L cold start rough code 43 gas odor

My 95 Suburban runs rough when cold started and there is a strong gas odor. There is a trouble code of 43. The colder it gets, the worse the problem is. My shop is stumped. Any ideas. Thanks.

The code 43 concerns the knock sensor, web site: www.troublecodes.net (http://www.troublecodes.net). The strong gas odor ? Is the engine a TBI ? Had a 1/2 ton with a throttle body and one of the injectors was leaking.

Yes, It's a throttle body injector system. Thanks for the idea.

Any solution snakeis ?