Had the joy of cleaning my EGR a few weeks back. 22 cans of carb cleaner, a dremel tool, and a high/headache that will remind me to crack the garage door next time, I deemed it clean enough and the pintle movement free.

I sprayed some carb cleaner into the intake and output ports where the EGR attaches, started the engine, and was treated to streaks of brown liquid under the hood. Ran it for 10 seconds, thinking it was long enough to clear the tubes.
Reassembled. All ran well (50 rpm lower and searching for stable idle)

Regrets:

1) I had NOT blown out the EGR valve w compressed air. I was so happy I had gotten the thing so clean I just forgot.

2) Also, every now and then (every few seconds, there will be what feels like a weak firing at idle. Not a misfire -- it is definitely firing, just with reduced intensity. No SES no misfire codes).

I then realized that although spraying carb cleaner into the exhaust port on the engine (EGR INTAKE) would dissolve carbon and shoot dissolved scum into the air, I neglected to consider the fate of the carb cleaner on the intake port on the engine (EGR OUTPUT).......

Since the EGR is usually only open at low and maybe med-light throttle, the pool of scummy carbon liquid was probably sitting at a low point, and only getting moved along for combustion when the vacuum in that port is high enough AND /OR when the EGR os in the OPEN position, and the force of the recirculating exhaust gases pushes some of it though to combustion, fouling the a/f mix and making for weak firings.

It also may explain the P0172 Rich code I got shortly thereafter, because the crap being pushed through richened the mixture in an "unmetered" way.

The weak firings are pretty much gone, but I have to clean the valve again and blow it out this time. I should be able to tell if I have gotten rid of the carbon juice from the exhaust port on the engine by seeing what's gunking the valve now. I would have thought by now that carbon juice would have been eradicated long ago, but it seems to have taken 2 weeks.

Hey-- I've cleaned Saturn EGRs 1/2 as well as this before many times, but never sprayed the inlet or outlet ports on the car.

This time I'll actually THINK before I act.
-----------------------------
You only learn stuff by screwing it up now and then

 

I was able to go for round 2 Sunday.

Cleaned the EGR valve again. Not much came out.
Since the P1404 is for EGR CLOSED performance, I spent an inordinately long time working the spring on the pintle while trying to clean its bore -- which, unless you want to start putting #00 steel wool or something else ever so slightly abrasive between the pintle and the bore--is rinse push release rinse push release. I made sure that the pintle snapped back to the closed position. Blew it out w compressed air.

Now the fun part.

Wanting to further clean the exhaust port on the engine that fed the intake of the EGR, I started and ran the car with the EGR off. THIS time I wore my protective ear covers, but it was still loud as hell. I got under the hood and used a thinnish rag to meter the air sucked in by the port feeding back to the throttle body and therefore control the rpm, which wide open would pin at 4k compliments of the rev limiter when car is not moving. USE a THICKish rag --mine kept getting drawn into the port on the engine (not good).

I managed to get a rhythm going by where I would get the rpms down to about 1500k, then spray carb cleaner in the exhaust feed till it almost stalled, then slowly let the rpms rise by uncovering more of the intake port, then pull the rag away and peg the rpms at 4K. Then a few low to high rpm bursts and I could see misty crap come out w the exhaust. Did that till there was no more mist. Reattached EGR.

There is a documented history of some older saturn s cars either losing track of the correct V measured in the fully closed position or having the value shifted in the PCM memory. I have read many posts in the past where people have cleaned cleaned cleaned, kept getting the code. Then they went out and bought OEM EGRs (which are not cheap), drove for a little while, then got the code again, then warranty exchanged, installed, and coded again.

I've seen suggestions that d/c the battery for a little while will force it to redetermine the closed zero value. I do not believe that but I did it anyway today.

I've also read that a PCM flash is needed to address since value is stored in non volatile memory.

I figured, hell this is going in for inspection in 2 days (hence my attention), might as well check and do all that I can to make it run its best.

Pulled the plugs. 2, 3, 4 nice tan. Closed the gaps a bit -- plenty of electrode left.

#1 -- barely hand tight, soaked in oil. Some on bottom of boot but not wicked up.

More importantly, the plug had a small piece of the ceramic insulator missing at the top on one side but the rest was intact.

I'm assuming that plug was the cause of the intermittent random weak firing I described earlier. It was always firing, but if the spark was dancing around and not always from the center of the center electrode, it would be a weaker spark.....replaced with an old but serviceable NGK matching plug ---no more weak firing.

Did a throttle body cleaning since the air intake was already off for the EGR. The body and back of the plate were not too bad so I concentrated on the IAC.

Result: Idle 850 +/-5 rpm for the most part.
--------------------
Oh yeah, it's inspection time TUESDAY
If I pass 5K mi for the year it must have the OBDII readings done.
If I don't pass 5K mi for the year it is emissions exempt regardless of whether the SES light is on.

I have about 100 mi to go --- 10 to get me to the inspection location and I think I need 50 mi to finish the catalyst monitor readiness. I've never had to drive a true gm drive cycle. I just drive around for a few days, check the monitors, and eventually they all go Ready.

I'm thinking I'll go for it, try to get the monitors all ready, and not run out of miles.
If it codes, I keep it under 5K mi

More later when something good or bad happens.

 

Ok Tuesday AM. Spent last evening visiting w mom and of course driving my sc2 to get there AND to let the monitor tests run. Came 90% of the way home, all but catalyst were complete. Drove another 20 min on the interstate, catalyst complete. Time to go home.

I actually have about 100 mi left before 5,000 for the year, so as long as they don't drive to West Virginia and back on the safety inspection drive, I should be good.

 

Good luck with a successful inspection!

 

Thank you.

I figured out since i last posted that
1) the flow out of the egr goes straight to the intake manifold (duh) not the throttle body
2) there APPEARS to be a backyard fix for recurring P1404s on "not so new"/poor quality EGRs where the true issue is wear. Since the error is generated when the EGR is commanded closed and the "closed position " voltage does not match close enough to the ORIGINAL closed position voltage when the EGR was BRAND new, until you can get the system to re-learn the closed position voltage, you're SOL.

Personally, When I have had to replace EGRs on my Saturns, I have gone OEM (2/2). They did not fail w P1404s however.

So if triggering a relearn is the goal, you can either
1) flash the PCM, which , upon next startup, learns the new closed position
2) SUPPOSEDLY Do what is suggested here Pontiac Grand Am: DTC code P1404 ? Car Forums at Edmunds.com

My hope is that the Saturn S-car PCMs shared enough in common w prev gm PCMs in areas like this that they react the same. One way to find out......
------------------------
Basically

with car off

1) unplug EGR wiring harness
2) turn key to ON
3) Erase code --when confirmed erase, then IMMEDIATELY TURN OFF IGNITION (apparently part of the key to this trick)
4) reconnect the EGR wiring harness.
5) Next ignition cycle will trigger a relearn of the closed position voltage and all will be well.

Hopefully I won't need to try this, but if I do, I'll upate this thread as to whether it works on our S cars

 

That sounds like a simple enough procedure to do, derf. Let's just hope all your hard work took care of it and you won't need to do this.

 

Passed inspection this morning w 80 mi to go from crossing into non exempt for emissions. But I drove around after I cleared the code. All 50 mi to complete the dang catalyst test. I wanted to be positive all monitors were ready in case this turned out to be something where I had to replace something for safety and it ran the mileage over 5K mi.

All done for another year.

 

Congratulations! Keep that car on the road as long as you can.

 

Hey, popped another 1404 on the way home. I've proven that I can, with the correct timing of events, have the monitors all ready and no pending or hard codes at inspection time, so that doesn't seem to cause an issue.

What causes an issue is that it keeps popping a 1404 and MIGHT not be fixed with a new one. I'm gonna try that voodoo stuff i quoted above --- once I get a replacement for my very nice but pricey bluetooth dongle that made only 1 more reading after I took it out of the finished wash cycle. There was no water inside that I could hear.

I always double check jeans pockets before doing a jeans wash. My other half does not. So my OBDII (including CAN) bluetooth dongle is ruined.

I always check shirt pockets before washing. My other half does not. 5 hours ago, she washed a shirt of mine with a nice bluetooth earpiece in it. Ruined.

So I'm down a earpiece and a dongle but won a bonus P1404 all in the last 6 hours

Oh, and managed to break the O2 sensor loose on my neighbor's pickup but could not reach through from the bottom w two hands to separate the wiring connector. Everything on that 2005 chevy truck is an unnecessary pain.

Been up most of the night throwing my resume around to more sites......

Just dozed off w elbow on desk

gnite.

Please send money

 

Hey derf, I'm reading back through this thread and see where you said you used 22 cans of carb cleaner. Is that right? 22? Or was it just 2? I haven't used 22 cans of carb cleaner in the past 10 years, I'll bet!