Hello all, and thank you in advance for any help i get on this issue.
I have a 98 mercury sable wagon with the 24 vlave durotec engine. It is a great car, and i would recomend the purchase of one to anyone looking into a used vehicle. I am baffled by the code i have recieved, as i have tried everythign recomended by the dealership to fix it, to no avail. I need to pass an emissions test in the next 1.5 weeks, or the battle wagon is gone forever.
Here is the history:
1)code p0401-replaced egr sensor as ford and mercury vehicles are notorious for throwing out their sensor. cleared the codes
2)code p1401-took sensor back off, found the new part to be faulty (one bent electrical connection)-took it back to autoparts store and exchanged it, also bought new hoses as switiching from the aluminum to the plastic model requires an extra inch or 2 on both the HI hose and the REF. Took out valve, saw it was entirely caked with carbon, replaced it for good measure. checked all the skinny red and green hoses connecting the vacum to the valve and the intake. blew through each one seperately, no apprent blockage or cracks, they all blew through easily enough, and were not able to blow through with the ends covered.
Replaced all parts, and with confidence, started driving to reset the codes. SES light turned off....turned towards the epa service station, light came back on.
3)code p0401 again.
According to the list of probable causes..the only part that is not new is the vacum (is that the same as the evr?), but everyone tells me it is extremely, highly unlikely that the solenoid actually be faulty. is there any way to test it mannually? Is there anything else i can do to find the problem? How likely is it that the pcm is the problem, as it continues to detect the insufficiecnt flow-if it was bad, wouldn't it be detectimg more things than this? Please help me.....i'm new to home auto repair, and this is a terrible first experience. I could really use some advice
You did replace the DPFE sensor? Do you have access to a scan tool that can run a KOER (key on engine running) self test. If you do once you start the self test take a vacuum gauge and remove the hose from the top of the EGR valve and see if there is vacuum present, at least 5in. If you do then the EVR solenoid and vacuum line to the valve are working. Next what you can do with the engine running apply vacuum to the EGR valve manually with a hand held vacuum pump, if the engine stumbles the EGR valve is working. If that still doesn't isolate your concern make sure you get a DPFE sensor from Ford and not a parts store. Just to make sure you have the correct sensor for your engine calibration code. hope this helps.
Yes, i have replaced the dpfe sensor. Went another route last night, and i am hoping to get some opinions on what is going on. Took off the throttle body and cleaned the gunk out of the C-shaped port after the throttle body gasket, which is a part of the cast mold of the intake. I would suggest that anyone who throws p0401 look into cleaning this before going out and dropping $$$$$ on new parts. It was caked solid, no wonder there was insufficient flow.
Using throttle body cleaner, a thin metal wire, some pipe cleaners and a whole lot of paper towels, i got the passage cleaned out and ready to run. Reassembled everythig and got some really strange results.
a)engine idled really low and hard...to the point of shaking the entire car. It stalled a few times, average idle was .5 on the rpms meter. very low for my car, with a normal average of 1.5 or 2.
b)accellerating reved engine very high. very high. a slight touch to the accelerator sent me flying down my alley.
c)smoke after i shut the engine off. lots of smoke.
So.....is this my engine burning out the throttle body cleaner that got inside (very high alcohol/acetone content in the throttle body cleaner, makes sense to me that it would burn very hot)? Is this my engine getting used to being able to breathe? Or is this my engine saying "take me out back, bring a rifle, and do the humane thing."? I detatched the negative power cable to reset my idle perameters and the obd II system anyways, and it is sitting at home for the rest of the day. While i'm at work, i am looking to ensure that i will not be further destroying my car in some way.
I have heard that in removing the throttle body and cleaning it out, that others who have done this same measure in order to get to the c-Shaped egr port have had a few stallings and hard starts before their engine was back in order.
What do you all think? should i be scared out of my wits, or what?
ok...so i think i have the egr problem fixed, unfortunately i can't exactly find out if i'm right. This post will have 2 subjects
(Oh, and to the other mike out there, somewhere, thanks for tipping me to airing out the the throttle body, you're right about that rick guy, right on! and to rick? You rule!!!!!)
1)the EGR: Anyone else researching the egr code p0401 on a sable or taurus should definately go through the pain of taking off their throttle body and cleaning out that port. definately. it is the problem, if the sensor didn't work, i guaruntee it! Do not replace the valve until you are out of other options. But be careful! that retention clip that was in the way of your post screw on the bottom right part of the throttle body? It will get stuck behind your gasket and cause all kinds of removal problems when you notice!
2)my real problem, a low idle. really low. like, moving the engine back and forth low, i mean, sounds like my car is dying low. like, "please, kill me now before it gets worse" low.
The smoke went away fairly quickly after another restart, and airing out the throttle body made the start very smooth. but now, both the other mike and i are experienceing the same problem, a very low idle. when accelerating there is no issue, at least not audibly, i moved the throttle conrol by hand to rev the engine, and the sputtering went away. the old battle wagons, apparently, like to do this....darn grocery getters. who needs duals on a wagon anyways??? seriously. it's a station wagon!
so-is it the air idle control valve (whatever that is, i guess i'll find out at autozone tonight)? or, like i was asking before, could that solenoid vacum (i think it is called the evr) be causing all of this grief?
where else do i look for a vacum leak? all the egr hoses are back on and right, and i don't know what else i could have knocked out of place.
for any interested, i got it. The other mike with a 97 taurus tipped me to a vacum leak between the throttle body and the intake manifold. With him it was a bad gasket-for me, i was an idiot and didn't move the spark plug wire retention clip out of the way before reattatching. Moved it, used a lil sealant, and now i'm off to pass an emissions test. Thanks to all for all of your postings in other threads that led me to the answer. and thanks to Rick @ free-auto-repair-advice for the difinative problems.
Also, thanks to mike, for obvioulsy being better at home auto repairs than I
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