P0401/P0402 Deadline Set

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Bluetribal

Bluetribal

10 Year 15 Year
Joined
Mar 14, 2006
Threads
280
Messages
6,004
Location
Sandy Eggo
Website
www.markkuz.com
Man, I have had the dreaded engine light since March of 08' and now I can't even remember if it's a P0401 or 402 code at this point. But I just got my DMV renewal notice today and my two years are up and I have the big STOP sign telling me to get a Smog at a test only station. So I have until Sept 2nd to get this code fixed and cleared.

Anyone else with this code that wants to get together and go through the tests to diagnose the problem? Two heads are better than one and threes a gathering while four is a Party!!!!

Date is set for Saturday June 27th in South Park, San Diego. I will PM my address & phone number if anyone needs it.
 
Last edited:
PO401 fixed

Mark,

I just defeated my PO401 (which I believe you also have). I had my CEL since just after buying it.

I went through and checked all of the EGR bits and ended up replacing a bad VSV for EGR and the vacuum modulator. The modulator filter was black on the underside, this was the only reason I replaced it. I believe the black filter indicates a bad diaphragm.

I changed my VSV in no time. I removed it a few times so I have it down and did not remove the intake plenum as the FSM directs.

I'm in SD so I'll be happy to help. I'll be easy since I just did mine.
 
Mark, double check what code is popping up for sure. I passed throwing a CODE 28 I even had the check engine light on when i pulled up. (it does help to know the smog person) Truck passed with flying colors still.

Says in your own post its the 401...
https://forum.ih8mud.com/80-series-tech/225392-can-i-pass-ca-smog-p0401.html

Some guy said he even passed with a 401, by just clearing the code before heading into the SMOG station.
 
Yeah, I will just clear it if I don't get it fixed in time. But I really want to get it fixed since I am sick of seeing that Check Engine light. I usually cover it with a business card.... Out of sight out of mind right...


Reid, what are you doing back? Name your time and place, it will just be good meeting up with you again.
 
I just had this code pop up again yesterday and need to diagnose what is causing it and fix it.

I can get together any weekend except July 25th - Aug 2nd when I'm on surfacation in Mex.
 
Bluetribal said:
Yeah, I will just clear it if I don't get it fixed in time. But I really want to get it fixed since I am sick of seeing that Check Engine light. I usually cover it with a business card.... Out of sight out of mind right...


Reid, what are you doing back? Name your time and place, it will just be good meeting up with you again.
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I was really sick of seeing my CEL also. I could clear but it would come back on in no time.

My wife's job brought us back. Our business did not pan out due to the $#!t economy, however, it is still in the works. We just moved this Saturday. SD weather is soooo nice!

Whenever you want is fine. Dan, you and myself can tackle both rigs. BTW: I removed my VSV, tested, discovered it was bad, replaced it, went inside and called CDan. In other words, you don't have to fix it right away, but we can at least try to find the problem.
 
Yeah I just want to diagnose the problem and throw my $ at the item that will fix it. I might just buy the small vacume lines and replace them since it can't hurt.
How about this coming Saturday since Sunday is Fathers Day or next weekend? Because then it's July 4th and then the following two weeks are OTL and I will probably be their one or both weekends.
 
Bluetribal said:
Yeah I just want to diagnose the problem and throw my $ at the item that will fix it. I might just buy the small vacume lines and replace them since it can't hurt.
How about this coming Saturday since Sunday is Fathers Day or next weekend? Because then it's July 4th and then the following two weeks are OTL and I will probably be their one or both weekends.
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The next weekend would be cool for me. We'll probably still be unpacking this weekend. We'll see what Dan can do.
 
I can do either weekend but the next weekend would probably be best, just let me know day, time and place.
 
I have that same issue, would you guys take another broken truck and pair of hands if available?
 
This sounds like a great opportunity that I could have used a year ago to solve my P401-402 problem. I managed to get it done over time. My turned out to be a combination of 4 things. First was a bad modulator 2 minutes to replace. Then the o2 sensors, what a pain this was, stripped bolts, finally took to a muffler shop and had to helicoil a new stud. A loose connection at the VSV solved for a month or 2. Then I started replacing all the the small vaccum lines, then the larger ones, maybe $15 in parts, many were hard, cracked, and anything but air-tight. The hose replacement finally defeated the codes. "Knock on wood"

I would strongly suggest replacing all the small vaccumm lines while you are at it. I would call CDan and get at least 2 lenghts maybe 3 of what he sells. I believe it is sold in 1 meter sections and I used 2 1/2 full meters. It is an odd metric size that I could not find at napa. Some are close in size but not a great fit. This would also be a good time to replace the PCV valve and breather hose at the same time. I did alot of the service manual testing on the parts which found the multiple problems. From what I remember several others found the same. It seemed like very few only had a single issue especially if they drove with the code for a while. My 2 cents anyway, which is maybe worth a broken shirt button.

Good luck and report back on your solutions and pitfalls.
 
We are definitely replacing vacuum lines. This is something we can fix/replace right away. I bought a few feet from the local NAPA. No need to get vacuum lines from Toyota. Custom bent hoses like the PCV to manifold yes, but not regular vac lines.
 
Bluetribal said:
I am happy to offer up my place. We can fit two cruisers nose to nose in the driveway and rotate a third in or just park it in the street under a nice shade tree.
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Cool. I'll supervise from under the shade tree. :flipoff2:
 
Speaking of EGR shtuff: This month is the first smog check I've had to perform on this rig. Due to a DMV error, I was driving around the first year without being "legal" in CA. I had plates, stickers, and the registration card, but for some reason, my vehicle was never entered into the CA database.

I was pulled over by an officer about a year later, who was randomly checking plates. He asked me why he had no record of my rig. I said "What?". He says "Yeah, your vehicle does not exist in the California Vehicle Database. Can you explain?" What the what!?!

Well we got it resolved and now two years later, smog time.

Just though I'd share . . .
 
I have a canopy that we can put over the two nose to nose in the driveway but that's assuming the June gloom is gone..

What size hose did you get from Napa... I will score some of that and some carb cleaner too. Any special tools needed?

And Sat or Sun next weekend works for me.
 
Two sizes and I'm not sure what size they are. I drove to NAPA, pulled off the hose from the manifold to the EGR valve and the little section of larger hose from the VCV (by the dipstick), went inside, and got the correct size. I got 4' of the smaller line and 2' of the larger. Overkill, but I prefer extra rather than be short.

A ratcheting 12mm wrench and lots of 3/8" extensions are the ticket to getting the VSV for EGR switch out from under the manifold. IIRC a 12mm, 14mm, and 10mm sockets are also needed. Loooong pliers are also nice (for the vacuum lines). We can get that sucker out in less than 15 minutes.

I'll have my tools.

Next Saturday is cool with me also.
 
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