O2 Sensor CEL & P0401 Questions

Gman86

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Few questions i need answered by some people with experience on 2.3L motors.

1. Does the throttle body need to be removed when pulling the upper intake plenum open for egr port cleaning or can it stay connected?

2. What are the torque specs for the upper intake plenum bolts?

3. Is throttle body cleaner ideal for egr valve and port cleaning and what are a few tips/pointers to ensure proper cleaning?

4. The only gaskets that are needed are the upper intake plenum gasket and egr valve gasket to do this job properly is that correct?

5. Are the 02 sensors upper and lower the same pitch and thread? I know they are both 4 wire connections is the only difference harness length?

6. What is the best way to re-connect a cut 02 Harness? Please keep in mind i do not have the resources to solder. Is male/female connections or finger binding the wire together and heat shrinking a viable temporary fix?

Thanks for any input. - Rick
 

xci.ed6

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1. Does the throttle body need to be removed when pulling the upper intake plenum open for egr port cleaning or can it stay connected?

-I think it can stay on, just pull anything attached to it, wires, cables, etc...



2. What are the torque specs for the upper intake plenum bolts?

-IDK...maybe around 20lb/ft (m8) to 30lb/ft (m10)




3. Is throttle body cleaner ideal for egr valve and port cleaning and what are a few tips/pointers to ensure proper cleaning?

-carb cleaner, the real stuff! Clean it when your done. Use a wire brush, you can get round ones for tubes from a gun shop to clean gun barrels. I grip mine with vice-grips, not the rod thing.




4. The only gaskets that are needed are the upper intake plenum gasket and egr valve gasket to do this job properly is that correct?

-pretty much-




5. Are the 02 sensors upper and lower the same pitch and thread? I know they are both 4 wire connections is the only difference harness length?

-same thread, if you're using cut-n-match stuff cut them with them plugged in -AFTER- you loosely thread in aftermarket.





6. What is the best way to re-connect a cut 02 Harness? Please keep in mind i do not have the resources to solder. Is male/female connections or finger binding the wire together and heat shrinking a viable temporary fix?

-crimp connectors. the ones with built on heatshrink ends. I use those on most repairs
 

james'99

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1. Does the throttle body need to be removed when pulling the upper intake plenum open for egr port cleaning or can it stay connected?

That can stay on. Be careful with the intake gasket. I messed mine up and smelt gases from the EGR until I got back in to replace it.

2. What are the torque specs for the upper intake plenum bolts?

16 ft lbs per Haynes

3. Is throttle body cleaner ideal for egr valve and port cleaning and what are a few tips/pointers to ensure proper cleaning?

I used brake cleaner for everything personally. Just a matter of using cleaners and something to scrape out all the carbon. Compressed air can be your friend if accessible. (Take xci's advice and use carb cleaner.)

4. The only gaskets that are needed are the upper intake plenum gasket and egr valve gasket to do this job properly is that correct?

If you're careful, you can save the plenum gasket, otherwise, right on.

5. Are the 02 sensors upper and lower the same pitch and thread? I know they are both 4 wire connections is the only difference harness length?

Yes. Same thread and pitch.

6. What is the best way to re-connect a cut 02 Harness? Please keep in mind i do not have the resources to solder. Is male/female connections or finger binding the wire together and heat shrinking a viable temporary fix?

I wouldn't heat shrink unsoldered wires... How about splicing them?
 

xci.ed6

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really, research connections.

'raw' joints of less resistance than solder joints when fresh! You need to prevent corrosion, solder does this, but keeping out water does too.

When I was a VW technician, this GTi came in with 'stereo doesn't work'

10941431_10100676835688369_5944536398444121223_n.jpg


derp, I wonder why? hahaha

so I repair:

10404098_10100676835693359_8819331367929158968_n.jpg


Notice heat-shrink crimp connectors! Not soldered! Solder tends to make crap more brittle also, especially where it will get moved around. Like under the d/s seat like this.

Bonus, wrapped, clean, I marked the wire with the yellow stripe to indicate 'repaired'

10489984_10100676835658429_1552050948708434042_n.jpg
 

james'99

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I guess the vicinity it's in is very prone to water. Haha! But yeah. I'm not sure. Best thing to do would definitely be replace the sensor but if you're in a pinch, go with xci's plan of attack!
 

xci.ed6

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Try some of the heat shrink bits, they are also filled with hot-glue, of some type. So when you heat them to shrink, they also ooze glue. They are stuck for sure!
 

Sino

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Another vote for the heatshrink crimp connectors, I suck at soldering and those are a very reliable godsend.

It would be easier to clean the top half of the intake without having to worry about the more sensitive bits on the throttle body. Carb cleaner works, bead blasting is an exorcism.
 
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