CEL code P0400 on 98ES with 5 spd swap

[eksz]

98ES with 5 spd swap. CEL just came on. I pulled the trouble code and got P0400 ERG Flow Malfunction. Cleared the code and it was back next time I drove the car. I've read all the TGC threads that popped up after searching "P0400" but have a few questions to sort out what to do next.

1. I’ve read p0400 is a generic code for ERG problem. The MIts specific code is either 0401, EGR insufficient flow, P0402 (excessive flow) or 0403, EGR solenoid malfunction. Anyway to determine if it is really a 0401, 0402 or 0403 code without having to buy a Mits specific code reader? Anyone know if the code reader Autozone uses will provide more information beyond P0400?
2. Some say to change out the gas cap others say a bad gas cap will cause a different code and has nothing to do with P0400. Thoughts?
3. One thread stated the likely cause for P0400 is the EGR solenoid valve, the vacuum hoses going to it or the differential pressure sensor (this may not be applicable to 7g). How do I check this out?
4. What do you use and how do you clean the ERG valve? I ask because another thread stated P0401 is insufficient flow and P0402 is excessive flow. Insufficient flow could mean either a partially blocked EGR tube, blocked EGR pathway in the intake, sticking EGR valve (stuck closed), or a malfunctioning EGR solenoid. Excessive flow could mean that your EGR valve is stuck open and needs to be cleaned. Might also mean the solenoid is stuck open. Start with inspecting and cleaning the EGR valve

[finald8ta]

I have the same issue only thing is I started getting this code when I switch out the fuel tank because it was leaking,
This is what I found out
http://mitsubishiforum.com/forum/eve...egr-flow-6692/

Granted I'm swaping over to an outlander mani this weekend I won't kno for sure if my TB is clog till i remove it and inspect my egr system.

HTC EVO 4G

[mko]

p0400 is EGR flow code regardless too much (which is impossible) or too little. Its very likely the EGR is clogged by gunk build around the valve and holes. Get it out and clean it. $3 Chemitool from walmart and an old toothbrush will do it. Before that you might wanna get a small flathead and poke around the walls and try to scrape as much shit as you can.

Thats the cheapest thing to do.

Insufficient flow could be also that the valve doesnt open at all which meant that the solenoid or the check valve isnt opening.

Start by cleaning it, clear the code and see what happens

[eksz]

Posting info from Finald8ta's link here for anyone looking into this problem in the future. This info was provided about a 2000 V6 Galant: If you want to check your EGR system- simply pinch the vacuum hose on the top of the throttle body with the yellow tracer with the engine running. This is the vacuum bleed hose. Blocking/pinching it will eliminate the escape path of the vacuum thus applying vacuum to the EGR valve (causing immediate stumble). With the sensitive emission system on all late model OBDII systems- it's not that you don't have EGR flow, the check engine light is on because you don't have ENOUGH or because you don't have immediateEGR flow.
Most common remedy? Removing the intake hose and cleaning the ports on the top side of the throttle body bore (specifically the EGR source vacuum port- hose with green tracer) usually eliminates the problem. Do this by wiping the bore with a rag soaked with throttle body cleaner. Be sure your getting your fingers deep enough into the throttle body (think back 2 Jr high school ) to reach the ports. If that doesnt do the trick- there is a vacuum restrictor in one of the vacuum lines going to/coming from the vacuum delay valve (hose with white tracer) that can become clogged or partially blocked significantly lowering the amount of available vacuum to open the EGR valve. This part of the EGR vacuum circuit may not be easily seen or accesable. If you are able to access it, you can replace that section of hose with a similar sized vacuum hose eliminating the restrictor altogether.

Of course, you can check the EGR solenoid by applying power and ground to it to see if it works. (this should be done 1st just to eliminate this as a suspected source of failure)

[mko]

just remove the vac line at the TB with the engine running and put you finger there and see if the vacuum pulls it, or if you have a boost/vacuum gauge will work too

[finald8ta]

I get nothing when I did that, no vac or anything . I'm thinking its because of my cracked IM.

HTC EVO 4G

[eksz]

Sorry for delay in getting back, work and Montana's cold weather got in the way of working on the G. Reminder: Car is a federal emission speced 98ES (not CA specs) so it has two small vacum hoses to the top of the throttle body (TB). The hoses plug into two brass pipes on the top of the TB. The brass pipes are labled P-E-A. The location labled P does not have a brass pipe so I assume it is permenately blocked. Per the chart from my Chilton's manual (P4-42; center diagram) the hoses should have green or yellow stripes. The hose to the A pipe is not color coded (it should have been green) as it goes to the E pipe and the yellow hose goes to the A pipe.

With the engine running, if I pull the hose from the E pipe there is suction from the pipe but nothing from the hose. With the E hose pulled the engine RPMs increase. Put the E hose back on the E pipe and the engine idle drops and engine stumbles a little. When I pull the hose from the A pipe nothing happens; no change in RPM. Also there is no suction from either the A hose or the A pipe.

[mko]

Are you running stock TB? It sounds like its a 90 1g eclipse TB with just two vac lines

[eksz]

Totally stock. The 98ES with federal spec has only two hoses connecting to the two ports (small brass pipes) on top of the TB. There is a place where a third pipe could go but there is nothing there. I've owned the car since new so I know it is stock. I can grab a picture if desired. Per the Chilton's manual the 94-97 has three hoses running to the ports on the top of the TP although the routing of the 97 hoses varies from the 94-96.

[mko]

yeah, pictures will work better i guess. TB and lines and where they go.

[eksz]

Here are pictures: This from the chilton's manual

[eksz]

Here are pictures from the car: TB detail, Note: there are hoses to the E and A ports but the P port is blocked (that is the way it came ).


Expanded view of TB and hoses:


Vacum hoses going down behind the intake mani

[mko]

The R line is the same, in your case is connected straight to the manifold and in earlier models it still goes to the manifold, but thru the TB 3rd nipple.

As I said before, check the solenoid and that control valve. I hope you cleaned the EGR already.

EDIT: The code wont reset itself, you have to clear it.

[finald8ta]

ok granted this is a 7g, it the same setup on an 8g, just this weekend I did the outlander swap and the car was running great till last night on the way home when it wouldn't hold idle, its doing the same thing ur car is doing, and the p0400 code has nothing todo with this sence I still have that code, so I get home pull a line off the TB and the car starts to idle fine, check all lines for leaks, I got nothing, swap out the silenoid, still did the same thing I put my hand on the egr and connected the line to the TB again and the egr is working, once its open the car idles like crap again, I still have to swap out the control valve and see if that helps, ill post up later with my results, as for the p0400 code I been having a lot of pressure in the tank and a hard time putting gas in as well not sure if my vent line is blocked or what, that's another mission ill get to, what I think what might be the cause is another sileniod at the tank, mind you I had to swap tanks because I had a leak and I been stuck with this code since.

[finald8ta]

ok I got some good news I switched out the check valve and got It to idle fine, bad new is when I was disconnecting another line it came back, pluged it back in and the idle was still there and the egr was open, disconnected the vac line to the egr idle came back plug the line to it and all is good for now, hope this helps u out,

I did notice that when it starts to pull vac and the egr starts to open, I give it some gas and the egr will close, and idle fine,
it could be ur egr valve that's bad..
good luck
and as for that p0400 code I will get back to u on that,

[mko]

Its supposed to stumble when the egr opens, but it shouldnt die. The IAC should compensate for the pressure dpor registered by the MDP sensor.

Oh I forgot, make sure you clean the MDP sensor on top of the intake manifold. The hole under it too. That sensor verifies that the EGR works