Chrysler Repair: 1997 LHS: misses/stalls at highway speeds, side exhaust manifold, exhaust gas recirculation valve

Question
While at freeway speeds of 60mph +, slight jerk,then car loses power
have had computer replaced and programed,fuel line was replaced so was a censor. Car has been to Chrysler dealer as well as another mechanic, no one seems to be able to get to the bottom of this problem, by the way once you bring car to a stop it seems to recover itself,also, it does not to this every time. HELP HELP I have spent waaaay too much money, approx 1000 +

Answer
Hi Rhonda,
I assume that no fault codes are set in the new computer and so you are looking for something that doesn't set a fault code. The two parts I would suspect are the catalytic converter and the exhaust gas recirculation valve.
If the catalytic converter had a loose or clogging-up honeycomb element that might well manifest its problem only at higher engine rpm. That could be assessed at an independent muffler shop (I would stay away from the chains because they are more likely to want to replace it whether it needs to be or not).
If the exhaust gas recirculation valve stem was cruddy that could cause the stem to prevent the valve from closing when you accelerate the engine, which it needs to do or the engine will miss. And if the problem is marginal it could be intermittent as you describe. The valve is located along a small pipe that branches off the passenger side exhaust manifold and heads toward the rear of the engine, hidden unter the intake manifold. You will find that it has three parts: the valve body is mounted to the pipe, the round top with a couple of vacuum hoses, and in between a flange inside of which is the valve stem. You will see a slot is tne stem into which the tip of a screwdriver can be inserted. Move the stem back and forth and you will feel spring-action trying to close the valve. It should do so firmly to a dead stop. If it doesn't move quickly to the stop then spray some WD-40 on the stem where it enters the body and exercise it some more. See if that ends the problem the next time you are on the highway.
Neither of the parts I suspect are well-monitored by the computer so they are prime suspects.
Please let me know what you learn.
Roland

PS: Sorry for the delay but I just found your question in the "pool" to which it had been referred by the other expert. Please 'rate' this answer; where you see the qustion about 'volunteer of the month' consider a 'yes' if I have been helpful to you. Thanks