EGR problems on 98 Camry

[russtyk]

I am getting a check engine light and the code says the EGR valve is bad. I put a vacume on the EGR valve to open it and the car still runs the same. It should idle rough when the EGR is open. Remove the EGR valve and tube, cleaned them both, did not find and obstructions and still getting the code. The EGR did hold a vacume so I do not think it is bad. Any ideas what could cause this?

[RIP]

What was the code?

[russtyk]

error code is P401

[RIP]

http://www.obd-codes.com/trouble_cod...n-flow-egr.php OR...
http://www.obd-codes.com/forums/742-...ns-please.html OR...

This is from the Camry FAQs thread at the top of the forum:

P0401
After the engine is warmed up, the intake manifold absolute pressure is larger than the value calculated by the ECM while the EGR system is ON (2 trip detection logic).

Possible Problems
EGR valve stuck closed <= Most common Clean EGR valve
EGR Vacuum Switching Valve (VSV)
Open or short in VSV circuit for EGR
EGR valve position sensor open or short circuit
Vacuum or EGR hose disconnected
EGR valve position sensor
Manifold absolute pressure sensor malfunction <=See P0105 above for testing MAP sensor
ECM

The Factory Manuals thread at the top of the forum should list the manitenance manual for your model year. In it you should find troubleshooting procedures and specifics for your EGR system.

[papirringo]

you need to replace the egr valve and the vsv

[russtyk]

I have taken the EGR valve off, checked it and cleaned it so I do not think it is bad. Possibly the VSV, I have not checked it, where is it located. I think it is on the back of the motor someplace. This is the 4 cylinder motor.

[papirringo]

on the egr valve, one of the vacuum lines goes to the rear, between the fire wall and engine, that line goes to the vsv, but even if the vsv passes the test, replace it. why?, it gets sticky, and it might be good at times, and I would replaced the egr valve too but its up to you

[RIP]

Originally Posted by russtyk

Possibly the VSV, I have not checked it, where is it located.

It's not shown in the factory manual?

[russtyk]

Just replaced the VSV and reset the codes. Will wait and see what happens. Can they put that thing in a more difficult place to reach?

[russtyk]

Replaced the VSV and still get the error. Not sure what to replace next.

[papirringo]

ok, since you apply vacuum to the egr valve when the car is running and nothing happends, you just found the problem, "it sould run rough or stall" if not, repair or replace the egr valve.

[russtyk]

When I apply the vacuum to the egr valve, I can put my hand behind it and feel it opening. Also took it off and cleaned it and made sure air flowed through it.

[papirringo]

ok, that's a smart idea, and the last thing to check is the modulator, the one next to the valve, sorry I didn't mention it before, after that, you have nothing left, besides vacuum lines

[lilhoodlum86]

so did u find the problem?? im getting the same problem....i cleaned the EGR valve

[russtyk]

Still have the problem. I think it may be something in the head of the motor that is clogged.