DEQ problems (1 Viewer)

[Catsxb]

Not sure if this is the correct section but here it goes:
Had the catalytic converter stolen a couple years back. Replaced the converter and failed DEQ. Did my "drive cycles" for over 1000 miles and failed DEQ again. Replaced the radiator and all coolant hoses and failed DEQ again with a "EGR" "A" "FLOW INSUFFICIENT DETECTED". I've put Lucas in my gas tank. I can't think of any part I HAVEN'T replaced already. Any suggestions? Thanks again!

 

[baldilocks]

Looks like you need to address the EGR system for that P0401 code.

 

[unclegit]

Was this the NE station just off 33rd ? I was there at 1:00 pm today doing my '97.

Weird they flagged the catalyst as my report says unready also and the truck passed.

I've had intermittent P401's - but I just clear the code and it generally stays off for 6 months at a time - certainly enough to get through DEQ. At some point this summer I'll do the valve guide seals and clear out the passages as best I can while I'm doing it.

 

[Shipwreck]

Yep. You need to check out the EGR and vacuum system.
One of the most common causes of P401 is the vacuum switching valve. Pretty easy to do the continuity tests described in the FSM. Make sure that stored codes are cleared before you go in for testing again.

 

[Catsxb]

Looks like you need to address the EGR system for that P0401 code

 

[Catsxb]

Thanks. I really don't have any idea what I'm looking at so that's helpful.

 

[Catsxb]

Was this the NE station just off 33rd ? I was there at 1:00 pm today doing my '97.

Weird they flagged the catalyst as my report says unready also and the truck passed.

I've had intermittent P401's - but I just clear the code and it generally stays off for 6 months at a time - certainly enough to get through DEQ. At some point this summer I'll do the valve guide seals and clear out the passages as best I can while I'm doing it.

No. Ha ha. They failed me the first three times though. I don't have any lights on my dash that show any sensors being triggered so either they're burnt out or I don't know.....

 

[Catsxb]

Yep. You need to check out the EGR and vacuum system.
One of the most common causes of P401 is the vacuum switching valve. Pretty easy to do the continuity tests described in the FSM. Make sure that stored codes are cleared before you go in for testing again.

Appreciate that. I don't recall replacing that.....yet. This is a steep learning curve.

 

[Shipwreck]

Search FZJ80 PO401 ih8mud via Google and you will discover a long list of possible causes here. From my experience a failed VSV seems to be most common. Clogged vacuum ports, leaky vacuum lines and EGR modulator run a close second.

 

[unclegit]

If you've no CEL on the dash it's burned out or someone removed the bulb - it's an easy fix.

When you start the truck does it light up ?

I'd replace the bulb and reset the code and see if it reappears = you may get enough time before it triggers again to get through emissions

Then go ahead and properly address the issue of the P401.

Where in Oregon are you ?

 

[Catsxb]

Search FZJ80 PO401 ih8mud via Google and you will discover a long list of possible causes here. From my experience a failed VSV seems to be most common. Clogged vacuum ports, leaky vacuum lines and EGR modulator run a close second.

I'll check that out and then have a look through my manual and see if I can repair/replace myself. I'm in thousands at this point. *sigh Thanks!

 

[Catsxb]

If you've no CEL on the dash it's burned out or someone removed the bulb - it's an easy fix.

When you start the truck does it light up ?

I'd replace the bulb and reset the code and see if it reappears = you may get enough time before it triggers again to get through emissions

Then go ahead and properly address the issue of the P401.

Where in Oregon are you ?

I'm not sure? I'm a female that knows nothing about trucks but trying to learn because mechanics are expensive. As for the lights, seatbelt light, brake light.... regular stuff. Are these fixable things I can find in my Haynes manual? I'm in DT Portland. I appreciate your time.

 

[unclegit]

First up grab the Toyota manuals for the truck and ditch the Haynes - you can download them here : https://forum.ih8mud.com/resources/1996-fzj80-fsm.27/ The Haynes is OK - the Toyota manual is gospel...

These trucks are pretty easy to work on - so don't let it intimidate you. I'd reset the code first with a code reader and see if the code reappears immediately. Autozone can help as they have code readers - you can have them scan and reset the code for free, or if you're going to be doing a lot of your own work grab a cheap bluetooth OBD2 adapter from amazon that can link to your phone with an app like dashcmd and it'll let you reset the code.

Handy thing to keep in the truck in general if you are planning on doing your own work.

Fixing any burned out warning lights is a matter of a removing a few screws and a bit of swearing to pull the gauge cluster out - not that hard at all.

When you first start and turn the key to ACC position - the truck the CEL light should light then go out as you start the engine - directly below the x1000 rpm.

 

[subzali]

This thread might help

P0401 Defeated - with pics

I started to throw a dreaded P0401 code that was constant, and recurring immediately after clearing. I have the FSM, and read God knows how many EGR and P0401 threads - More than enough burn my eyeballs and confuse the hell out of me, so I decided to dive in. Preparation - I had decided to...

forum.ih8mud.com

 

[Catsxb]

First up grab the Toyota manuals for the truck and ditch the Haynes - you can download them here : https://forum.ih8mud.com/resources/1996-fzj80-fsm.27/ The Haynes is OK - the Toyota manual is gospel...

These trucks are pretty easy to work on - so don't let it intimidate you. I'd reset the code first with a code reader and see if the code reappears immediately. Autozone can help as they have code readers - you can have them scan and reset the code for free, or if you're going to be doing a lot of your own work grab a cheap bluetooth OBD2 adapter from amazon that can link to your phone with an app like dashcmd and it'll let you reset the code.

Handy thing to keep in the truck in general if you are planning on doing your own work.

Fixing any burned out warning lights is a matter of a removing a few screws and a bit of swearing to pull the gauge cluster out - not that hard at all.

When you first start and turn the key to ACC position - the truck the CEL light should light then go out as you start the engine - directly below the x1000 rpm.

View attachment 3903247

Nice! Downloaded and done. This is amazingly convenient when I'm out on the road. I'll put those items on my shopping list. And the swearing is free.....I got that part already.