Chrysler Repair: 2000 Chrysler 300M: rough idle when stopping, exhaust gas recirculation valve, 2000 chrysler 300m

Question
I have a 2000 Chrysler 300M. When I come to a stop light or stop sign and apply my brakes, my car idles like it's going to shut off. So far it hasn't just shut off but it really idles like it's missing (like a jerking motion, everyone in my car can feel it). It only happens when I stop in traffic, driving on the streets it's fine. My car has abot 145,000 miles. I had a tune up completed two years ago.  

Answer
Hi Margo,
A couple of suggestions:
See if you can get a free fault code readout at an Autozone parts store and if not possible look for a special offer from a shop to do the readout of the engine controller memory. It should be around $40 for that. Get the fault code numbers (4 digits preceeded by a P), what they mean, and an estimate for the repair. But then write back and we'll double check on that before you authorize the repair. Tell me which size engine you have (it should say a number followed by an L on the valve cover).
Second, take a look at the exhaust gas recirculation valve (egr). That valve will cause just the symptom you experienced if it is not closing firmly when you take your foot off the gas because the mixture will be too lean and that cause the engine to miss. It is located at the rear of the right cylinder head. It may have an opening between the valve body and the valve control solenoid where there is an opening that has a rod inside of it. That rod is the valve stem, and it has a circumferential slot that allows you to move the valve back and forth with the tip of a screwdriver. It should also move on its own accord when you rev the engine and let it drop back to idle. With the tip of a screwdriver inserted in the slot try moving the stem by hand against spring action (opening) and let the spring close the valve. Then see if the valve is really at the end of its motion (closed) by the screwdriver touch. If not, then spray some WD-40 on the valve stem where it enters the valve body to free it up so that it closes all the way.
Those are the first steps I would take. Don't opt for an expensive repair unnecessarily.
If the roughness is only associated with putting your brakes on (e.g. it idles ok in neutral with no brakes being applied), then I would look at the large vacuum hose that connects the intake manifold to the power brake booster (located directly in front of the driver in the engine compartment, in line with the brake pedal. Make sure that the hose clamp on either end is attached firmly and tightened down. If there were a leak in the hose (or possibly the brake booster) that could also lean the mixture and cause a miss.
Roland