TeamSwift

SMOG TEST PASSED WITH FLYING COLORS!!! ZERO NOx!

********PLEASE NOTE THE CORRECTION IN MY LAST POST--I DID NOT HAVE TO REPLACE THE FLANGE BOLTS OR GASKET! Exhaust leak was from faulty welds of the Cat. Converter that I had had installed last month.....************SO, NO PANDORA’S BOX AFTER ALL!

Did you do the LIVE TEST? Does it move when the RPMs are increased? If not, maybe you need a new valve. Does it hold a vacuum--say, 10 psi for a minute or so?
I'd recommend you take a look at the kick-fix references I mentioned in regard to the map sensor and manifold vacuum's involvement in the system, and how they might apply to you...but he, like the others, says most problems emanate from a clogged exhaust head portal.

Though my manifold bolts & nuts looked nasty -- rusted -- and the nuts, especially, were worn away some, putting WD40 or PB Blaster on them a few days before worked wonderfully for me--you will tell right off the bat if they will be a problem. For me and others they came off "like butter". Yours might surprise you, too (unless you are next to the ocean?). I would have liked to have replaced the 3 Grade 8 12mm? nuts, but my local parts stores didn't have them in stock. My bolts and studs were fine.

For me, the EGR valve itself was terribly clogged. Soak it in a can of parts cleaner (from Autozone--Kragen doesn't carry it) & thouroughly clean it, including the two ports. (Alternatively, you can spray most of a can of carb cleaner into a glass jar). I used a scratch awl, a heavy duty large paper clip, and some Qtips in the end. Spray it out with carb cleaner and/or Seafoam & make sure it is clean. Just some Autozones, and I think Pep Boys, carry the Felpro gasket (for 99 cents, or $1.49) (not Kragen). I had to spray some gasket remover on the manifold EGR surface--it was quite messy. You'll definitely need a new gasket.

You said, "I'm willing to do the roto-rooter on the passage in the head from the exhaust to EGR valve, but don't want to go doing anything deeper." I'm not sure I understand what you are saying. If you mean you are willing to move the ex. manifold out of the way -- clearing that passage in the head was the HARD part, just because of the time involved (and some risk) with dealing with the manifold! Once you have the auger drill bit, it made clearing it out very easy -- it maybe only took ten minutes. Using a cheap speedometer cable to properly finish the job (all the way to the EGR portal) was EASY, once I stopped trying to use my drill to do it. It would clean out the "U" tunnel in the manifold, too (possibly with the additional aid of a coat hanger or 1/8 " galvanized cable from a hardware store), and also the intake manifold passage. I'm not sure I needed to use that other cable I had, with the little ball on the end, but since I used it before the speedo cable by hand only, I'll never know....And I also did not try the galvanized cable with just my hands, before using that cable....
Most people seem to find the head tunnel to be 90%, if not the whole problem (besides the EGR itself). But I wouldn't want to push the stuff into the exhaust manifold, by only inserting a cable into the EGR exhaust portal....could damage the Cat.
Don't let your 200SX experience pollute your brain. If you do what I did there is NO more passage left to be cleaned, or to have pieces break off. Use lots of carb cleaner & seafoam, & even put seafoam into the intake portal with the engine running, at the very end, and I can't imagine there being a problem after that. Note Kragen did not carry the spray Seafoam....

GOOD LUCK!

Excellent!

_________________
1992 Geo metro, 1.0L 5spd, 511,000miles on original engine & trans
- First time engine work at 456K miles, bad headgasket. Rebuilt head, Felpro gasket installed.
- knuckles/hubs/brakes/13" wheels from a 2000 Metro, running 175 70R13
- New bearings and 1st/2nd synchros at 440.5K miles.
- MPGuino
- Averaging ~ 51MPG these days

Quick question about air blowing the passages. With the EGR valve off, through the hole coming from the exhaust manifold I can blow through the passage just fine (after I cleaned it). It seems to let out as much air as I want to blow into it. But when I try to blow through the other hole, the one where the exhaust leaves the EGR valve and heads to the intake manifold, that one doesn't want to let hardly any air through it. I have to really press the blow gun hard up against the hole / port for it to stay. Is there a designed restriction that limits the exhaust going into the intake, or is it just really really clogged somewhere in there?

It's the latter. Mine was crusty in there. I used a thin metal wire to shove in there, and gumout to soften things up.

_________________
1992 Geo metro, 1.0L 5spd, 511,000miles on original engine & trans
- First time engine work at 456K miles, bad headgasket. Rebuilt head, Felpro gasket installed.
- knuckles/hubs/brakes/13" wheels from a 2000 Metro, running 175 70R13
- New bearings and 1st/2nd synchros at 440.5K miles.
- MPGuino
- Averaging ~ 51MPG these days

Jellybean you are spot on. Driving around the car today I got the P400 EGR problem and I had just totally cleaned the EGR valve and it was operating like butter. Since the exhaust piping was clean, and the EGR valve was functioning, either it was the modulator or electronic controls (heaven above help me) or it was that intake section. I took off the EGR valve (again) and double-checked to see if any air was passing through the intake like Jellybean said it should do in quantity, but what I thought previously was a small amount of air was in error - nothing was getting passed, it was totally blocked. Luckily, I was able to clean it and let me post how because there doesn't seem to be a ton of info on cleaning the intake side. Again as Jellybean said, when you blow air into that right-hand hole (what you see when the EGR valve is off) it all should come out without restriction in the intake (you can hear the air escaping down the throttle body). If you don't get tons of air coming out, it's clogged like JB said. I'm reiterating this because had I not ignored it I would have not have to have done most of the steps twice.

First, the passage that leads from the EGR valve outlet back to the intake has several twists to it, making using the coat hanger trick less effective. You can get it in there part way but I couldn't get a breakthrough. The other thing I was cautious about was I didn't want to get any kind of non-evaporative liquid in the cylinders. One of the other posters talked about having to remove the spark plugs and using Q-tips to suck up the excess cleaner he used to clean the passage out once and I didn't want to do that, so the only way was to make sure not to blast that kind of liquid through the clog in the passage. I didn't know if carb cleaner evaporated quickly like brake cleaner, if it does then you may not need to do as many steps as I did.

So here's what I did. First I started with the coat hanger to try and jab as much as possible. Then I used the thin straw on the carb cleaner and blasted that in there nice and good, tons of black liquid rushed back out. Then, because I didn't want to risk getting that stuff in the combustion chamber and cause hydraulic lock, I then blasted some brake cleaner in until it ran back out less black than it started. Then, I got a length of speedometer cable, cut up the end to try to form some kind of auger, ran it into the hole as far as it would go then used my drill to spin the cable. Remove cable then clean the end. Then, put the compressed air blow gun up against the passage hole and try to blow. If it doesn't blow through, that means it's still decently clogged. Repeat all steps except the coat hanger: blast in the carb cleaner, blast in the brake cleaner, hit it a bit with the speedometer cable auger, try to blow through it with air. It took me about 4-5 cycles of this until finally I heard the gratifying "pifpt" of the air breaking through and then the rush of the air being pumped in, actually leaving. At that point since I knew the passage was unblocked I sprayed in more BRAKE cleaner into the passage (still the passage that the EGR valve mounts to) and then quickly blew air through it, that way I got the brake cleaner in the passage to blow all the way through. I did that a few times until it felt like the brake cleaner had gotten a chance to get a little more crap off the passage walls where the clog was. Put it all back together and fired it up, took a little more cranking than usual due to all the crap that broke free and was injected into the passages, and maybe it was me hoping for the best but it sounded better than ever idling.

LOL, I forgot to actually test all the pieces in concert by applying vacuum to the EGR valve, I'll go do that. Anyway, point is there should be a completely clear passage along that intake passage and if not, get there to be one or you'll be like me and fight with it later.

Sorry for the long post, hope it helps someone.