p401 and no idle need help - Toyota Nation Forum : Toyota Car and Truck Forums

Fortified Souls · 07-12-2011, 01:41 PM

Hey toyotanation need help with my 2000 5sfe camry. It has the dreaded egr insufficient flow problem and keeps stalling when you try to let it idle. I have recently replaced the egr valve vaccum modulator and the vsv valve was replaced when I rebuilt the engine last year. I did not clean the egr pipe when I replaced it souls that be my next step. Not sure what else to do :-\.

***fenixus*** · 07-12-2011, 02:55 PM

if not already done, you can replace the EGR modulator too, it sits right by EGR valve on the intake manifold.

also check ALL vacuum hoses for a) no restriction/clog and b) if they can hold vacuum for at least 30 seconds (e.g. borrow a Mityvac hand pump from Autozone).

any problems with hoses, get them replaced, usually when they are cracked on ends, it means you need new ones. some ebay sellers from Taiwan sell silicone vacuum lines (metric) that fit EGR system perfectly fine, let me know if you need measurements.
Howevr for the lines on the back of engine, I would only use OEM hoses as they need special heat insulation otherwise they can melt.

and check that exhaust tube between EGR valve and cylinder head, it could be clogged with carbon buildup (also check opening on head, it could be restricted with a wall of carbon).

hill8570 · 07-12-2011, 03:09 PM

Quote:

Originally Posted by Fortified Souls

Hey toyotanation need help with my 2000 5sfe camry. It has the dreaded egr insufficient flow problem and keeps stalling when you try to let it idle. I have recently replaced the egr valve vaccum modulator and the vsv valve was replaced when I rebuilt the engine last year. I did not clean the egr pipe when I replaced it souls that be my next step. Not sure what else to do :-\.

OK, I'm a bit befuddled here. P401 generally means the EGR isn't opening up when the ECM expects it to. OTOH, the only way the EGR can kill the engine at idle is to be open. Might have two different problems going on here.

Can you keep the engine idling if you get it a bit of throttle? That probably would rule out the EGR being the cause.

Fortified Souls · 07-12-2011, 03:26 PM

Yes I can keep the engine on with a little bit of throttle and it will idle for a couple of seconds but any longer than that and it just cuts off. To fenixus I replaced the thing next to the egr valve already.

***fenixus*** · 07-12-2011, 03:38 PM

did you replace or check the EGR VSV (Vacuum Switch Valve), it's different from modulator and is located deep down on the back of engine. it could be stuck open causing the EGR valve to stay open too when unexpected by ECU (it controls it by means of switching ground connection on and off).

Fortified Souls · 07-12-2011, 05:30 PM

Alright I just got back from vatozone to see if any new codes had came up I now have p0401 which is egr, p0335 which is crankshaft position sensor and p0340 which is the camshaft position sensor, -_- Is there a fuse that I need to look for that controls both of those sensors? The car drives fine under load it just won't idle.

Fenixus I replaced the vsv valve when I put the engine back together last year. How often do they go out?

***fenixus*** · 07-12-2011, 07:37 PM

nah, if the VSV for EGR was replaced last year then it probably OK (good as new if it is OEM).

I'd rather look into crank and cam position sensors... but then I get confused here ... I thought the 5s-fe has only the crank position sensor (under timing belt cover) and you are getting the code for cam position sensor as well?? how can that be?

Fortified Souls · 07-12-2011, 08:29 PM

It has both in the 2000 year at least. Are there any fuses that they depend on because I think its weird for them both to fail at the same time. I had a problem once with the camshaft position sensor falling out once because of the vibrations my car has at idle due to having no balance shafts.
However, I fixed that with lock tight and the code went away. That was the first thing I checked for that but they are both connected up and fine. I would think that without them working it would be missing and sputtering but it pulls great I just can't get it to idle.

joede · 07-20-2011, 12:20 AM

Suggestions:

Do this first: Remove the vacuum line to the EGR then apply a vacuum to the EGR vacuum inlet. If the engine stalls then your EGR valve is OK if not the ERG valve is dirty or defective. clean or replace as required.

If EGR valve appears to be OK then do this:

Pull the cap off the EGR modulator then pull out the filter under the cap and blow off / clean with compressed air...these can get very dusty and impair air / vacuum flow.

If this does not clear the 401 code then do this:

Again remove the vacuum line that goes to the EGR valve. Does the car run OK or just a little rough after removing the EGR vacuum line? If so then your EGR valve is OK and the problem is probably your EGR VSV located at the back of the engine.

Regardless of when it was changed, the EGR VSV is notorious for sticking! It is a BEAR to remove and check but I think resistance between its connector contacts should be no more than 39 Ohms. It is usually the electrical part / switch inside the EGR VSV that fails.

On my 99 Camry 4cyl the EGR VSV valve and the cam sensor both failed during the same week!

Finally there is a post somewhere on this forum that details how to go about replacing the EGR VSV....like it requires taking off the front passenger side wheel etc.