service engine light came on in my 99 ford windstar, had the egr valve replaced, service engine light still on

Question

took the vehicle in again, put on computer, the same problem noted on the computer with the egr valve, then #4 cyclinder misfiring, replaced the spark plug, engine light went off for 20 miles, ran rough, put a bolt in to disconnect the valve, ran much better, replaced the egr valve again as was told it was the spring, service engine light off for 10 miles, ran rough, put the bolt in again. Better gas mileage with the bolt in the valve, but service engine light still on. Took to another mechanic, computer says the same, he hooked up the valve, admitted it that it ran rough, thought there was an air leak in the valve, clamped that, as tack was now jumping around, and couldn't hardly keep the vehicle running when slowing down for stop lights. Vehicle runs fine, took it back, had the mechanics hook the valve back on, clear the computer, vehicle ran terrible, service engine light came back on after 2 miles. Put the bolt back on, service engine light on, vehicle runs okay. Any ideas?

Answer 1

You have clogged EGR ports in the top of the cylinder heads underneath the intake manifold. I have seen this many times. The EGR ports to each individual cylinder will become clogged with carbon. Leaving one or two open. The EGR gas will be pumped into the open cylinders and cause an overabundance of EGR gas in them. Your #4 cylinder may be the only cylinder that does not have a clogged port. Too much exhaust gas in that one cylinder will cause a misfire. The intake manifold will need to be removed and the brass EGR ports for each cylinder will have to be cleaned of any carbon deposits. As, I said this is a common problem on the 3.8 liter and I have seen it many times. If the code was for insufficient EGR flow, a P0401 or P0402 then I would also replace the Delta Pressure Flow Exhaust sensor, or DPFE. The new redesigned sensors are better capable of handling condensation from exhaust gases. The DPFE will not cause a misfire concern, but it will still make the check engine light come on.

Answer 2

yugi29 is pretty close on this, but if the engine runs better at idle with the EGR valve unhooked, then I would say the the valve is getting vacuum at idle. That should not be happening. I would suggest that someone that has a "scanner" or knows computer diagnostics should take a look at it. I would say that the EVR(exhaust valve regulator) is either defective or being commanded to come on at idle,either way, it is something for an experience diagnostic person to determine.
by the way the DPFE is known to be an issue on all ford products,new one should be an upgrade if purchased from the dealer.
Hope this helps

Answer 3

I have a 1999 Ford Wind star LX and i never had the problem you are talking about but i had something similar to it with cost alot of money to try to find the problem when it turned out to be a bad fuse.Sry i can't be much help,but from my experience with my van if something goes wrong(even though small) it cost a fortune to find the real cause.

Answer 4

If you're still coming up with an EGR code after replacing the valve, try replacing the DPFE.

Answer 5

Disconnect the car battery for five minutes. The light should go out. If it trips again, there is another problem. O2 senors cause them to trip quiet often.

Answer 6

check with ford there maybe a hidden recall.I have a ford focus and my lights were shorting out and they fixed it no charge. the were aware of the problem

Answer 7

The problem is that it's a FORD, trade it in ASAP and get something buy GM or a Japanese model.... That will solve your problem

Answer 8

Probably need to reset the computer. Take it in.

Answer 9

check the diagnostics, or have them checked