Direction on how to clean EGR Valve on a 1996 Se
 

I am wanting to make sure that my linear EGR valve is not causing the P0171 code that keeps popping up every 200 miles or so,

I took the EGR valve off on Saturday and I could see that on the bottom there was a spring loaded valve with a torx screw head. I assume that this is the valve that opens and closes to let exhaust into the intake...I was able to insert a alcohol soaked swab and clean the shaft..what I could get to of it.

I wasn' t clear if should have opened it up from the top? It seemed like there were 3 screws that held the rounded top portion of the valve to the flange portion, but the heads for those screws must be inside the rounded portion, and I didn't see a way to get to them. Is there a way that the top comes off? to get to more of the shaft. The valve seemed to work freely from the bottom no hang-ups or sticking... Did I do all that I can safely do?

My bigger problem is that I keep throwing a 171 code once per tank of gas. I have tried cleaning battery cables and connections, I have replaced both the up & down stream O2 sensors. I sprayed starting fluid around all the vacuum lines and connections I could see, and didn't find any problems. I have close to 50 lbs. fuel pressure at idle.
The car seems to run great, I do notice that on occasion it seems to run a little bit rough idling in gear at a stop light..I can see the RPM's fluctuate (drop) slightly and I can feel a little bit of roughness...but very minor.

I did have a problem when I hadn't tightened up the EGR tube at the EGR where I was getting the 171 and a 304 misfire on cylinder 4. Found and tightened up the EGR tube
(I ihadn't tigthened poperly after doing intake manifold gaskets.) The misfire code hasn't ever come back and frequency of the 171 went way way down but it's still happens.

I am wondering if I have an exhaust leak.. Where are the most common spots for an exhaust leak that would cause a 171?

Any ideas welcome

Spit

The engine does sound a little loud at times and I am wondering if I have an exhaust leak

Yes the pintle valve is the spring loaded pat with the Torx head.

The pintle valve is spring loaded and should be air tight when seated. If the valve is not closing use something like dental tools to remove any carbon build up on the pintle face and shaft. You have to scrape off as much carbon as you can through both holes.

Spit... I do nothing more than spray TB/Carb cleaner into the valve and let it slosh around for a couple moments to clean the linear EGR.

Now.. let's get on to the real subject of your post. P0171 Lean Bank One. Right now this code is your best buddy. It's peeving you with no end in sight.

First off.. using Search and P0171 should net you many of my posts on the subject.
1. Check for vacuum leaks, ok..now check again.
2. That EGR you are looking over... the tubes at the intake and exhaust manifold like to crack easily. I mean EASILY. When I pulled my motor apart recently, I discovered a cracked tube at the exhaust manifold....somehow I wasn't surprised.
3. Look at your evap solenoid, double check the lines going to it. Is the port labeled "CAN" going to the evap canister by your driverside headlight, it needs to be.
4. Did you clean your MAF lately?
5. (Thanks Foghorn) Remove your battery connections and remove the rubber boots, check your cables for ANY corrosion. If you do not remove the boots (pull the bolt out and they slip right off) then you may not know your issue. Then follow the cables to the ends at the block and starter.. remove all, clean and reinstall.

All of the above can fix the Lean Bank code. The question is..which is your issue

Listen well to Boosty. He and the P0171 code were best buddies for a long time. They hung around together.

My problem is the 171 code.!!

Cleaning the EGR was one of the items that I thought could be a problem and I wanted to eliminate it..be sure what I had done was right. I thought I read in a Haynes manual not to spray any cleaners into the EGR (linear or digital) but to use alcohol on a swab to clean? So that's what I did.

I have cleaned the throttle body..I thought pretty good but I can clean it some more.
I have new plugs and spark plug wires, a new gas filter and new transmssion filter anf fluid, I did all that just because the care was at 96K when I got it. I did change the rear O2 sensor 4 weeks ago when I got a code on that, I just changed the front O2 sensor and it almost seemed like it threw the 171 quicker with the new O2 sensor than the old one. There are no plug wires touching the O2 sensor, and no O2 sensore wires contacting the manifold.

I have cleaned the battery cables and the connections at the battery a few times. I took the termianl end out of the rubber boot andi brushed it with a brass brush on both sides, till it looked like a new penny.

The 171 is so random. I can drive 200 miles and not see it then up it pops. I did check for Vacuum leaks but they are easy to miss and I will check again.

RE: The points that you made about the Evap soleinoid. That''s all the stuff sort of running pararell to the front valve cover & fuel rail, right? ...I did have all the lines disconnected when I did the upper and lower intake manifold gaskets. maybe I hooked it up wrong I can double check...there are 2 ports on the front of the throttle body that lines hook up to. One of the lines goes down to the canister, if I'm not mistaken. Can you confirm for me which of the two ports..upper or lower, that line should hook up to. if someone had a good photo of the front of the engine on a 96se that would show the vacuum tubes along the front of the engine it would help me confirm that I got it right.

I bought the car for my 85 year old father-in-law 6 weeks ago, and have been having a blast working on it. It's the nicest looking car that either of us have ever had. I drove it up to him from Columbus OH to Toledo OH on Easter Sunday. It had thrown the 171 earlier on Saturday after doing the front O2 sensore. I re-set it and drove 150 miles mostly at highway speed, but some city driving too, and never saw the code. It may be a week or 2 before I'll see the car again. I told him not to worry if if comes back it's a minor adjustment...but I would like to get it right for him so he doesn't have to worry about it...and if the CEL light comes on he knows that something may really need attention. He may only drive this car for another year or 2, my mother-in-law has never driven and never will so. I would be amazed if they drive it more than 2,000 miles a year

Thanks for the help and anything you can suggest or add is greatly appreciated.

Spit

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The reason why the code came quicker with new O2's is because you old ones were a little slower on the pick up.

The code is set becasue the O2 picks up and reports to the PCM that more fuel is needed. The PCM exceeds it's expected thresholds and reports that it's adding the extra fuel to you.

Check those vacuum lines on the front valve cover (L36 motor). I know this one from experience.. ;)

Were the cables corroded under the boot before you brushed them? I've seen and replaced my cables because the corrosion was down in the cable and the power difference because of it..set the code.

Last thing is..check the EGR tubes for cracks. Right at the base where it is bolted to the manifold. That's the normal crack area.

All of these except the cables are vacuum leak related and will cause a P0171...

Yes, there was some corrosion. It seems like the negative battery terminal is a little stripped, I have to be careful not to overtighten it...don't know if that's a concern? I have purchased an extra long battery bolt and could (haven't yet) replace it. Past experience is that the longer bolt can find some more virgin/solid threads deeper in the terminal, I know I can tighten an externded bolt down too far...so I have to be careful with that too..

I'll check out the other items on the list too. The cracks in the EGR tube is intriguing.. I also saw a post where the exhaust manifolds themselves were cracked.

Again thanks for your help..I'll report back


Spit