PO401 Defeated!!

[johnbelcher]

Well this 1k ohm 5 watt dude seems to have worked pretty well for me. Not a single 401 in 9 months.....

However....I am getting the occasional 402 now. About once a month. Usually when I am at cruising speed.

 

[Bear80]

If you get the 402, the resister you used is not within its stated tollerances. 1k or less should keep EGR tripped check engine lights off indefently.

BTW, I did finally trouble shoot my issue a while back and it turned out to be the VSV. It's odd to me that ones on a '97 would fail more often than other years, which is the conclusion I've come to. Also the EGR passage in the intake was nearly cloged shut. Just as a note, I never did have any carbon in the vacum lines and replaced the modulator years ago.

Also while doing the HG on mine I've come to the conclusion that the EGR is the vain for blown gaskets. "Head gasket creep" is the offical term but from my research it is common on cast iron to aluminium heads due to the EGR. It seems the EGR acutally has a COOLING effect that leads to the creep. That however, is for another thread. But the key to prolonging a NEW head gasket maybe the defeat/elimination of the EGR system. I say new because from my understanding once a gasket begins to "creep" it will never stop, and the only outcome will be for it to blow.

 

[Firedog]

Also while doing the HG on mine I've come to the conclusion that the EGR is the vain for blown gaskets. "Head gasket creep" is the offical term but from my research it is common on cast iron to aluminium heads due to the EGR. It seems the EGR acutally has a COOLING effect that leads to the creep. That however, is for another thread. But the key to prolonging a NEW head gasket maybe the defeat/elimination of the EGR system. I say new because from my understanding once a gasket begins to "creep" it will never stop, and the only outcome will be for it to blow.

I have been thinking the same thing for a long time now. I finally decided to attempt removing the EGR from my '93 completely, just went out and ordered the new EGR gaskets yesterday.

 

[johnbelcher]

What are "EGR gaskets"? Do they block off the gas flow back into the cylenders?

 

[johnbelcher]

Thanks for the resistor advice, Bear80....back to Radio Shack I go....

 

[Firedog]

What are "EGR gaskets"? Do they block off the gas flow back into the cylenders?

No, they are just the gaskets that go on the EGR and the tube ends to seal the connection

 

[lilevo]

Easy way to test the VSV is to pull it off and apply 12+ to the terminals. You should hear a faint clicking. If there is no clicking you can assume it is dead.

I found a similar solenoid with two ports from a 4Runner with the same plug. I used this in place of a $60 VSV and it works perfectly so far. No code.

 

[lndcruz]

does radio shack sell the correct resistor?

this is the closest one I can find on the web site

1k-ohm 1W 5% Metal-Oxide Film Resistor (2-Pack) - RadioShack.com

 

[jlg32281]

My check engine light has been on since I bought the truck a few months ago and this morning it's not on anymore. It was the famous insufficient flow code. A few weeks ago I cleaned the sensor and replaced a few vacuum hoses. I've driven a few thousand miles since then and it magically disappeared. At first I thought the bulb buned out, but when I first stick the key in, the bulb works. I'm not complaining, just curious if this has happened to anyone else.

 

[SeanAndHis80]

does radio shack sell the correct resistor?

this is the closest one I can find on the web site

1k-ohm 1W 5% Metal-Oxide Film Resistor (2-Pack) - RadioShack.com

That should be fine.

My check engine light has been on since I bought the truck a few months ago and this morning it's not on anymore. It was the famous insufficient flow code. A few weeks ago I cleaned the sensor and replaced a few vacuum hoses. I've driven a few thousand miles since then and it magically disappeared. At first I thought the bulb buned out, but when I first stick the key in, the bulb works. I'm not complaining, just curious if this has happened to anyone else.

If you had hardened, cracked and leaky vacuum hoses you may very well have fixed it. Time will tell.

 

[lndcruz]

That should be fine.

Yep worked, so far so good. Going on 3 days without a cel

 

[cdbridges1]

Yep worked, so far so good. Going on 3 days without a cel

Lndcruz, I also have a 95 that I want to do this to. Do you have a pic of where and how you used the resistor? Thanks!

 

[lndcruz]

Lndcruz, I also have a 95 that I want to do this to. Do you have a pic of where and how you used the resistor? Thanks!

Pic via gotmud's thread.

Which is the temp sensor plug with the probe cut off for the egr system located on the drivers side near the firewall on the intake manifold.

 

[cdbridges1]

Pic via gotmud's thread.

Which is the temp sensor plug with the probe cut off for the egr system located on the drivers side near the firewall on the intake manifold.

Got it, thanks! I wasn't sure if there would be different plugs across different years or not. I hopefully will get this done today. Fingers crossed no more cel.

 

[ShawnTRD]

I think I might do this. Is it something I can do living in NY with -05f to 90f+ temps in one day? Ok that might be a little extreme, but you get my point. Anyone with a picture of the installed piece?