104 Engine Codes

[BDBENZ]

I could use some help with the next steps in finding a problem with the running of my 1993 300E with the 104 2.8 HFM motor. It has had a stumble (jerk) at idle for a while now especially with the AC on, but does do it occasionally without the air, only at idle and when in gear. I recently have replaced the following items over the last 6 months.
Throttle actuator, OVP, plugs, wires, fuel pressure regulator, oxygen sensor, wiring harness in 2001, and had the head gasket replaced last week. The car has 72,000 miles on it. After the head gasket repair, the idle is beautiful, with out a bobble, but now I have drivability issues with a intake backfire at low speeds if you accelerate to quickly and a slow response to the throttle at low speeds but seems to perform better at higher RPMS. I double checked the cam timing and I believe it to be correct according to the procedure outlined by Steve B. in his article. I pulled the codes tonight and on pin 14, I get a code 10, the tn signal from the ecu and on pin 8, a code 9. What would be your suggestions on how to proceed on diagnosing what is the issue? Thank you for any help.

Bill