EGR code wont go away.... - Toyota Nation Forum : Toyota Car and Truck Forums

aflac · 12-02-2011, 04:31 PM

I have a 1996 corolla (1.8) and I just cant get the check engine light to go off so I can pass my yearly inspection. I've done the following but would love some advice if i've overlooked anything.

-clean EGR (twice)
-reset ECU (remove negative battery post for 15 minutes)
-clean all of the vacuum houses associated with EGR and vacuum modulator
-replace filter in vacuum modulator
-cleaned out the intake manifold (posted here, help out TONS! very smooth and slight power increase: DIY Intake Manifold Interior Cleaning)
-bought a NEW EGR valve

kickfli12 · 12-02-2011, 05:26 PM

hmmmm......

TheNightWolf · 12-02-2011, 07:23 PM

Has the light gone out at all?

aflac · 12-02-2011, 10:23 PM

The light is only off because I reset the ecu and stays off for approximately 12-15 miles.

kickfli12 · 12-02-2011, 10:37 PM

what code specifically is it?

aflac · 12-03-2011, 01:44 PM

P0401: Insufficient flow

Bitter · 12-03-2011, 02:24 PM

is the solenoid working?

aflac · 12-03-2011, 03:13 PM

The electrical solenoid close to the vacuum modulator? I have not but how can I check it?

Bitter · 12-03-2011, 05:53 PM

you can apply power and ground to it when its off the car to check it's operation, it should click open and closed and you should NOT be able to suck/blow through it when its either open or closed. If it fails to click or you can always blow/suck air through it then it's failed. On the car side of things it's harder to verify that the ECM is controlling it. You need a noid light connected in it's place and then run the engine under EGR operating conditions. The bulb should light when it's trying to open or close the solenoid.

speedy25 · 12-04-2011, 11:05 AM

Emissions stuff can really be a pain in the butt!

Quit throwing parts at the problem and try to get at the reason the ECU throws the code. Your EGR could be working properly but something else fools the computer into the EGR code. It is a problem with OBD electronics that the code is not always the problem.

Mosat egr problems are obvious mechanical or clogs from deposits. It does sound like you have worked it from that angle.

-SP

aflac · 12-04-2011, 01:57 PM

Off-topic: While looking around in the engine bay, I found out that my passenger motor mount is completely hanging off.

(thread to follow)

On-topic: I haven't checked the solenoid yet but I did replace a cracked pcv hose and might as well the pcv valve since it was only $3. Until the motor mount is fixed I can't put any miles on it for the ECU to read.

edit** Thank you speed25 for the write on the intake manifold cleaning.