96 Tracker P0400 Questions

kytrackerguy · 12-24-2007, 11:46 PM

I've been trying to clear this code on my truck for over two years now, the longest I have been able to get it to clear is a month, then it pops back on. Initially when I first started messing with it, I frequented the Zuwharrie and Zukiworld forums. After reading around there, the main concensus was to take the EGR valve off and clean it out. Well, I did that and in about 10 miles the P0400 code was back on. Tried this several times actually and always came back to the code being set pretty quickly following that.

I did some more searching on those sites, and found out there was a passageway in the back of the head. So I took off the exhaust manifold and reamed out the passageway. Took the EGR valve off again, cleaned it as well. Put it all back together.....again, a few miles down the road and the P0400 code lights up the Check Engine Light.

Fast forward until the next time I decide to mess with it, look around the sites above some more and I see all kinds of new postings about this tube that runs to the intake manifold. Mine has this....so I take that off, run some wire through it and clean it out really well. I also poke a screwdriver up in the hole leading into the intake manifold. I got a lot of carbon out by ramming a stiff wire and screwdriver....squirting a can or so of carb cleaner in there. Basically I cleaned it the best I could. Take off the EGR valve again, clean it some more, put it all back together....50 miles that time until the Check Engine Light came on.

Well, at that point I figured I had the passageways cleaned enough. I thought it had to be some sort of sensor malfunction, or the EGR valve itself was bad. I bought a Mityvac and proceeded to test things the best I knew how. Pulled vacuum on the EGR valve, it lifted and stumbled the engine and held until I released vacuum. I figure the EGR valve is alright (also lifted the valve by hand and engine stumbled). Next decided to test the EGR modulator. I couldn't get it to test according to how I've seen posted and bought a new one. I tested the new moduator prior to installing it into the truck, and it tested as it should. Installed it, didn't help either.

Ok, now I'm throwing parts at this thing because I'm not experienced enough to know what I'm doing. I came across a new EGR VSV on ebay and picked it up for $25 I think. Installed that, and it didn't help either. I've also replaced all the vacuum hoses with new hoses in case one was cracked or leaking. At this point I'm stumped and decide to search the Internet some more. Then I stumble on this site. There really is a wealth of information here.

I've read the various threads here dealing with the P0400 code and the cleaning of the passageways. One thread in particular is very interesting to me.

http://www.suzuki-forums.com/suzuki-...her-forum.html

I bet I've read Tracka96's post 100 times and do not understand about the passage behind the metal plug. So again, I got searching the internet and come across this.

CHEVROLET TRACKER / SUZUKI VITARA FORUM BOARD: Re: 1997 geo tracker "service engine light"

Low and behold, I come across another mention of this second passageway behind the cap in the plenum.

So now, to make a long post short....how does a person access this second passageway? I see in Tracka96's post about pounding out the cap and cleaning it that way. However, when I had the throttle body off cleaning it, I only saw one hole into the plenum. This hole lead from the tube and I saw this by inserting a long round brush up through the hole that this tube attaches to going into the plenum. Where is this second passageway?

According to the above thread "This is the #1 place where the system gets clogged. This is a pair of passages that are about 1/4" that are drilled out when the intake is manufactured that creat a 45 degree bend. One passage is capped off on the side of the plenum. It's in this passage that the clog happens. the passage is not drilleld out a full 1/4" into the plenum, but a small port that's about 1/8" is finally drilled into the plenum. This port faces the throttle body and when the EGR system opens up, hot exhaust gasses are blown into the plenum and immediately come in contact with the cold air ietring the throttle body."

Would anyone have a picture of this second passageway? Or am I misunderstanding something and there is not a second passageway? Up until a few days ago, I thought from the tube into the intake was just a hole about the size of a dime. Now this mentioning of a second passageway has just rocked my little world, haha! Someone please enlighten me, lord knows I need it!

I hope everyone is having a very Merry Christmas, and please....everyone also have a safe and Happy New Years!!

tracka96 · 12-25-2007, 01:49 PM

[quote=

[url]http://www.suzuki-forums.com/suzuki-sidekick-escudo-vitara-geo-tracker/19441-egr-fix-another-forum.html[/url]

I bet I've read Tracka96's post 100 times and do not understand about the passage behind the metal plug. So again, I got searching the internet and come across this.

CHEVROLET TRACKER / SUZUKI VITARA FORUM BOARD: Re: 1997 geo tracker "service engine light"

Low and behold, I come across another mention of this second passageway behind the cap in the plenum.

So now, to make a long post short....how does a person access this second passageway? I see in Tracka96's post about pounding out the cap and cleaning it that way. However, when I had the throttle body off cleaning it, I only saw one hole into the plenum. This hole lead from the tube and I saw this by inserting a long round brush up through the hole that this tube attaches to going into the plenum. Where is this second passageway?

According to the above thread "This is the #1 place where the system gets clogged. This is a pair of passages that are about 1/4" that are drilled out when the intake is manufactured that creat a 45 degree bend. One passage is capped off on the side of the plenum. It's in this passage that the clog happens. the passage is not drilleld out a full 1/4" into the plenum, but a small port that's about 1/8" is finally drilled into the plenum. This port faces the throttle body and when the EGR system opens up, hot exhaust gasses are blown into the plenum and immediately come in contact with the cold air ietring the throttle body."

Hi Ky, I didn't write that post, just found it and copied it. But, to solve my problem that seems like it was as bad as yours, what finally done it was poking around in that hole where the top pipe goes into the intake, using a wire and also a nylon gun cleaning brush, and also cleaning out the hole behind the throttle body butterfly. Been OK for a long time now. Tracka96

kytrackerguy · 12-25-2007, 03:32 PM

Tracka96,

Thanks for taking the time to write me back. Yesterday I went and purchased a bronze gun cleaning brush as suggested on this forum. I took the pipe off again and cleaned out the passageway as much as I could. I guess time will tell now if the code kicks again. As soon as I can get another throttlebody gasket, I'm going to take the throttle body off once again and clean the hole out from the other side. I am curious about the second passageway though. I guess I just don't understand why there would be two? Again, thanks for your time and have a very Merry Christmas!!

ogretracker · 02-03-2008, 05:31 PM

I just bought a 1996 tracker and it runs fine but has this p0400 code. A new egr valve was just put in and as seems to be pretty common the light came right back on. My question is if i dont try to clean out the system (which sounds like a never ending battle) and just leave it alone will it do any long term damage or cause any other problems. Thanks

tsteve · 04-01-2008, 01:40 AM

I think he is talking about the way the passage bends
It does a 90 into the plenum, so if you dont make that 90 it wont really be clean. OR, maybe he is talking about the little tiny port right by the butterfly, there is 1 on top, that you cant miss, and there is 1 more on the back side if I remember right... I just pulled the whole thing off and cleaned everything, I'll see how it goes for the next week or so

Anyway, the 90, if you follow the tube from the EGR into the plenum, it enters from the bottom, then does a hard turn. Right where the turn is, there is a end cap where they drilled the hole, I guess, without pulling out that end cap, it is really hard to clear out that passage, REALLY hard

So maybe he is talking about that port being 2 passage ways ? it's kinda hard to follow.

My tracker has a loud tick, or knock, when it is cold, I cant tell where it is coming from, even with a steth scope, but it completely goes away after I warm it up, and get the oil moving. Someone told me it may be a EGR problem. That and the fact my light is on, made me rip it all open this week to clean it all out. Hope thats the end for me, But I know it wont be

tsteve · 04-01-2008, 01:43 AM

I found a picture of the end cap, at the 90 where the tube gets clogged
Maybe this will help

P0400 Exhaust Gas Recirculation (EGR) Low Flow

ranger88den · 04-01-2008, 12:46 PM

ky, My 95 16v Tracker wouldn't clear my egr code until I cleaned the upper tube intake hole. I'm 99% sure this is your problem. Someone suggested a zip tie and this worked for me. It is rigid enough, when bent, to force the hard carbon out. I also used throttle body cleaner. Open the throttle body butterfly to see. Don't get confused, as I did, and think the brake vacuum port to the right (facing the throttle body) is the opening. It took a long time to loosen carbon, but can be verified by seeing the end of the zip tie in the intake manifold. Good luck

jtgh · 04-01-2008, 03:05 PM

Click >>>> EGR

see last frame on page.
see green tye wrap, thats the problem most cant find.

remove pipe and tickle it with bailing wire or a coat hanger cut in half.

photo by dan cove. on this forum ! thanks dan. real clear photo , and shows the path at the same time, graphics are great.

rumor has it pistol cleaning brush works best. brass or sst,

ranger88den · 04-03-2008, 11:55 AM

ky, Did you have any luck with the egr fix?

jtgh · 04-03-2008, 01:19 PM

some are unlucky and there really is a bad part.
99% clogged,
1% below:
EGR hose cracked.
EGR mod valve bad ( or you have no exhaust back pressure )
EGR NIPPLE TO MOD VALVE NIPPLE CLOGGED ( IT IS ONLY 1/16" IN DIAMETER AT MAIN EGR VALVE. LOOK there.
EGR VSV , BAD ,OR THE WIRES TO IT CUT.
EGR main valve , has a weak spring inside. (or pentile valve is sticking, etc)

if you get in a jam here , post telling the problem.tell what you have done.
there is a live test you can do , to prove it

some cars 95 and newer require, putting car on jack stands.
rear wheels up in air.
spin engine in gear to 3600 rpm and other requirments to watch the valve open all by its self , if it does not , then you have a hard failure.

PATH:
ECU>VSV >> EGR MOD (valve detects backpressure and gates vacuum to

EGR MAIN.

if engine is not fully hot , the EGR will never open. ECU waits fo that.

cheers.