hounddog

Could you have snapped the core inside one or more of the plug wires when taking them out? If the car backfires, it will often force debris back up into the injectors (carbon, etc.) and you will need to have access to a "pressure" cleaning system for the injectors (good germanic mechanics will know what this is and often have one on hand).

A4wheelin

I replaced them earlier this year.

Cdn Blue Coupe

Lots of good suggestions above but wires are probably the most likely.

A4wheelin

I think I have my old wires still. I should put those on and see if it makes a difference. I didn't check the gaps on the plugs. I should probably do that too.