Worth to fix? P0401

Your call, Sounds like you're tired of the car.

zythr said:

Your call, Sounds like you're tired of the car.

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I like the car, but it only worth $700~900 with currently condition. Change the VSV will cost me at least $80 and not sure if I need to speed more on the ERG system. ERG will be another $200.

I am just wonder if I keep running with P0401, what will happen?

I would just fix it... it's cheaper than buying a new car!

I think I know what he's asking.

Is it worth it to spend any money on this problem? As in will his car be hurt in anyway if he doesn't fix it?

I'm no professional by any means but from what I know, this could just means you have increased nitrous monoxide emissions. I have this same code on my dash and I'm pretty much refusing to fix it because from what I read it won't hurt my car in anyway. Like I said, I'm no professional, I could be totally wrong. Just my two cents.

Life2 said:

I think I know what he's asking.

Is it worth it to spend any money on this problem? As in will his car be hurt in anyway if he doesn't fix it?

I'm no professional by any means but from what I know, this could just means you have increased nitrous monoxide emissions. I have this same code on my dash and I'm pretty much refusing to fix it because from what I read it won't hurt my car in anyway. Like I said, I'm no professional, I could be totally wrong. Just my two cents.

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YES. That's what I am thinking about. Thanks dude.

I have had a 401 code for 1yr+. I didn't fix it. I had horrible hesitation and bogging at low RPM when it started. I put a new VSV sensor on it and it didn't fix it. I put a new EGR valve on it and it still would do the same. I disconnected the little vacuum hose on top of the EGR diaphragm, and it runs smooth with just the CEL on. I really don't care, nor does it bother me. Don't fix it, is my opinion.

The CEL comes on and off for these couple days.... It went off Wednesday and came up this morning again...

I've never got around to fixing it over the last couple years. Car runs great and I get get great gas mileage. Heck, I even passed a smog test (the check engine light stayed off long enough to pass) and the emissions were all well below the required readings. So, honestly, no I wouldn't bother.

tayunz said:

I've never got around to fixing it over the last couple years. Car runs great and I get get great gas mileage. Heck, I even passed a smog test (the check engine light stayed off long enough to pass) and the emissions were all well below the required readings. So, honestly, no I wouldn't bother.

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My dad had the same code for a few years. He couldn't get state inspection done from a bunch of places since the mechanics refuse to do it. We had to pay 100 bucks to get it done by someone who dares to do it.

I had a P0401 and a p0446. Both deals with the VSV valve. I when to the slavage yard, got two new (used one) replaced it. After 20 minutes of driving, the light when away and it had been 27,000 mile already. The p0401 is code for the VSV that sits on the engine block between the firewall and engine. One wire and two vacuum hoses and one bolt. Total cost, $2.

I found the old VSV to be jam with gunk. Clean the hoses and install the new one. I'll try to post some pics.

every time i see a p0401 I will recommend a vsv and modulator after confirming the egr is working (pushing up the diaphram and engine stalls).. ive done hundreds of them and never once had a comeback.. if your do it yourself its less than a hundred bucks. imho better than buying another car if all you need is a dd.

You guys are forgetting that the EGR system allows the ECU to advance the timing further than without it because it cools the combustion chambers which also reduces NOx emissions. More timing makes the engine run more efficiently when it can handle it. It's mainly for emissions, but it also has some beneficial effects.

Unless you run a JDM ECU, the USDM ECUs all have the EGR as an integral part of the ignition timing and AFR maps in the ECU, so when the ECU calls for the EGR, it will try to advance the timing. If it can't, you either get a knock correction (high timing retard), or generally reduced timing/engine performance during that time. You'll usually see problems with high engine loads and revs below 4200rpm.

The EGR deactivates after 4200rpm on the 5SFE, but below that, the ECU could be running a lot more timing WITH the EGR system operating as it should.

Yup. And you also don't overheat the pistons which can cause major problems.

well i'm not sure of canadian OEM pricing on parts but the holy trio for EGR cost like $250 max at online toyota dealer for a 97-01 4-banger.
egr valve $138
egr modulator $48
VSV for EGR $58
www.toyotapartsoutlet.com free shipping this month (UPS ground in US).

replacement of hoses (metric 3mm ID, 2mm wall) from ebay seller zenaracing is like $4 shipped per each 3ft/1meter or so. total rebuild of EGR sub-system for that model cannot be more than $300 US dollars including some shipping to Canada through a friend or so.

there are factory service manuals that might help you pinpoint the faulty part, but honestly (from own experience), just take a shortcut and replace all 3 of them and forget it, testing is not worth the time.
in my case valve tested good so i replaced the modulator first and then vsv (which tested bad due to bad ground behind intake manifold) and ended up replacing the EGR valve regardless on the end (old one didn't survive cleaning)...

decision is up to you.

also a bad egr valve which cannot fully close will kill the car's performance especially on acceleration. i had this intermittent problem and it went away finally after i replaced the egr valve with a new one (newer design also).