3.9 stalls when cold

I have a 96 3.9 auto with a stalling problem when the engine is cold. I have done the 3 turns on the key and the flashes indicate a loss of signal to the distributer while cranking and a O2 sensor circuit not fluctuating?
Code 11, 21.
Help

Thanks for the advise

I also have a 96 3.9 with the same problem. It developed mid-summer of this year. Had it happen about 4 years ago, turned out to be a clogged catalytic converter. I hope that's all it is this time. I will say, these things can go through some CAT converters. Mine is on it's 4th now - probably going to have a 5th soon. I wish I could just run it without one.

You can run it without one. It all comes down to where you live and your laws.

I am still looking for the gremlin. So far I have replace the distributer checked all the plug wires tried to replace the coil pickup but the truck wouldnt run with a new one. I returned the part as defective and the 2nd new part wouldnt run either.The one thing that seamed to work was I cleaned the crank position sensor. So far the cold start stalling has disapeared but I remain cautious this thing has stabbed me in the back before.

Anyway thanks for the headsup Ill keep my eye on the cat. Thanks man

Got the thing fixed, Here is what I came up with. I found article that
explained the chrysler electrical system from this I realized that no matter what the code that component may not be bad, The parts that run off 5 volt in series current include the crank pos. sensor,cam pickup,and the 2 heated O2 sensors. I replaced the cam pickup but the truck wouldnt run with the new part. I put back the old unit and changed the crank pos. sensor then the cam pickup. It worked. I still had the O2 codes so replaced bothI still had the distibuter missing at cranking and since the rotor was burning on the very leading edge I turned the distributer a quarter inch clockwise puting it within its range and the codes are all gone. The truck runs good
http://findarticles.com/p/articles/mi_qa3828/is_200105/ai_n8942314

This article will help all Chrysler owners