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Oxygen Sensors

1K views 14 replies 9 participants last post by  WickedSnake00 
#1 ·
Hey guys, so i just got a steal on an offroad H pipe. Before i install it, i want to throw some new Motorcraft o2 sensors in the front. My current ones, to my knowledge, are fine. But, I just figured now is the best time to do it.

I believe the front and rear o2 sensors are different right? I want to order them from Amazon because theyre cheap. Does anyone know the correct part number for the fronts?
 
#2 ·
I would say ask a dealer or go to a local auto parts store, as the OE sensors are Bosch made if I recall, and most auto parts stores will carry them.

However, if there is no issue, why spend all that money on new narrowband sensors? If anything, I would buy a wideband O2 gauge, and install that sensor, to get actual useful data.

ALso remember, you will be either using MIL eliminators or turning off the rear O2s in your tune, as with an offroad pipe you will get a CEL from them, due to lack of catalytic converters.
 
#3 ·
Oe are made by NTK.
NTK are damn near the same as motorcraft but slightly cheaper.

Front and rear are different. Don't remember if side to side are different, I don't think so.
Look on rock auto for the part numbers. Just get the front ones as like was said above, the rears are probably getting eliminators or tuned off unless you feel like looking at a cel
 
#4 ·
Get them from RockAuto.com. I believe they are the cheapest as I've always bought mine from them. They will show the Motorcraft part number, and yes they are also stamped with NTK. I believe svtperformance has a 5% off discount code so look that up or just google a discount code for them. For fronts I think it was $30-$35 shipped where a dealer wants around $70.

Motorcraft DY1039 is what you want for the fronts.
 
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#6 ·
Awesome. Thanks guys. Appreciate the help
 
#8 ·
Im going to bring a dead thread back to life instead of creating a new one.

long story short is this:

pulled engine and did seals, UDPs, cams, springs, timing, mid-pipe, long tubes, new PCV, new IAC, new o2 fronts, new plugs.

car runs flawless with the exception of it stalling when coming to a stop AFTER IT WARMS UP. The new o2s were NTK.

I cleaned the MAF during all of the work done. I figured if it was a vacuum issue itd be happening all the time instead of just after warming up.

Can somebody chime in and possibly give me some insight here?

the warranty on my o2s goes out on the 23rd of this month so if thats the issue or even a suspected issue, I want to go ahead and make some moves.

thanks in advance.
 
#11 ·
its on a startup tune right now. I did a datalog and sent it to my tuner but he says nothing looks fishy and said possibly a vacuum leak somewhere. Just seems weird to me that a vacuum issue would only happen at certain times but im not a mechanic by any means, just know a little about a lot.

Did you happen to put on a new throttle-body? New TBs and often old ones need to be adjusted. After the motor warms up it will go to a low idle which uses less airflow. If the TB isn't adjusted correctly to allow enough air to by-pass the butterfly valve you will see the motor surge and stall when coming to a stop. My idle was surging when coming to a stop and sometimes dying when slowing to make a turn.

If the motor is surging and stalling like that you need to open the butterfly valve in the TB a little. Standing at the driver's side of the car turn the throttle body stop screw 1/8 turn clockwise. If the motor is still doing it. Turn the stop screw 1/8 clockwise. The stop screw is not an idle adjustment screw. If you actually change engine idle you have gone too far. I did a test. I had to turn my stop screw over one full turn before engine idle was affected.

The arrow in the picture below points at the stop screw. Many after market TBs have a screw driver slot in the stop screw for easy adjustment. My BBK does. Stock TBs do not so you have to use vise grips to turn it.
not a new TB but it is aftermarket and possibly out of adjustment. i didnt think of this. ill give it a go and report back.
 
#10 ·
Did you happen to put on a new throttle-body? New TBs and often old ones need to be adjusted. After the motor warms up it will go to a low idle which uses less airflow. If the TB isn't adjusted correctly to allow enough air to by-pass the butterfly valve you will see the motor surge and stall when coming to a stop. My idle was surging when coming to a stop and sometimes dying when slowing to make a turn.

If the motor is surging and stalling like that you need to open the butterfly valve in the TB a little. Standing at the driver's side of the car turn the throttle body stop screw 1/8 turn clockwise. If the motor is still doing it. Turn the stop screw 1/8 clockwise. The stop screw is not an idle adjustment screw. If you actually change engine idle you have gone too far. I did a test. I had to turn my stop screw over one full turn before engine idle was affected.

The arrow in the picture below points at the stop screw. Many after market TBs have a screw driver slot in the stop screw for easy adjustment. My BBK does. Stock TBs do not so you have to use vise grips to turn it.
 
#12 ·
The IAC controls the idle RPM and the air going into the engine at idle....

This has vaccuum leak written all over to me OR it's a tune issue. It does go to Closed Loop when it warms up...it stays in Open Loop at cold start.

Will it idle at all when warm?
 
#13 ·
it idles fine when just started. It will idle great for around 20 minutes or so.... then eventually stalls itself. If im driving it and come to a stop (by down shifting or throwing it in neutral) it will kill itself instead of idle. I can manually keep it alive by giving it some gas but obviously there is an issue.

Before I pulled the engine (or replaced the original o2s) i had a random misfire code pop up here and there. Never could figure it out. (never gave a cylinder # just says random or something along the lines) After all the work, same code pops up here and there still.

This isnt my daily so i havent been driving it bc im afraid ill **** it up.....bc i just dont know what is wrong with it.

I have a shop that will run a smoke test for $100 so im thinking about doing that, i just wanted to see if anyone else had input before i did that bc i honestly am not fond of auto shops.
 
#14 ·
Do you have a wideband O2 sensor on it? That would be very helpful in knowing what the AFR is doing when it dies (going lean? staying good but just dies?) and what it is at idle and in general where it is when driving around.
 
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