O2 sensor location

Any number of reasons I would think failed sensor and broken studs .

From that picture that pipe has been there quite sometime .

Are you in a Emissions state to much work to repair just drive it till inspection then dump the vehicle

 

To much work to repair? Its not much work at all and will probably cost under $200

 

Myself it would have been fixed I was just pondering why someone would not fix it

When one goes to the Quickie Mart for oil changes crawling under the truck is most likely not going to happen.

To some $20.00 might be to much remember to some owners it is just a vehicle to go from point A to B not a family member

In fact I bought 10 of the bungs not to long ago just for that purpose

 

The more I think about it I think that it's very possible that the catalytic converter is bad. The truck seems to make a low crappy car noise with the engine on. Not sure if it's the muffler or the cat that makes it sound this way. I don't know if we are going to be able to afford it but I kind of want to change it all. Is there any way in testing for a bad cat and muffler?

 

I think I'm going to put in one of these clamp on O2 sensor bungs (

$58 AEM 30-2355-250 2.5" No-Weld O2 Sensor Mount

https://www.amazon.com/AEM-30-2355-250-No-Weld-Sensor-Mount/dp/B003ISI6TI ) to make sure that there are no other problems. The reviews all seem it works well. I just know that if we end up at a muffler shop here in So. Fl we are going to blow through our budget.

 

You should be able to find someone to weld a real one on if you pull the Cat out

The ECM looks at the values between the front and back sensors if the don`t change enough it gives you the PO420 code

Muffler if it is rusted and leaking exhaust time for new.

 

There's an issue. If I get a bung welded, how do I know which sensor I need? The original is the type with two studs and an oval gasket. The bung would be the screw in type. How do I know which screw in type is the right one? Thanks for the continued help.

 

You can get the proper ones to use oem style sensors

 

http://m.ebay.com/itm/170998012892?_mwBanner=1

 

As was said you can get the correct ones

I would not buy ones that would not accept the Denso Sensors I bought 10 they do come in handy it might be time to get some more.

 

Thanks guys for all the help. I believe that you guys are right. I should use all oem style parts. I spoke with one of the mechanics that works on our fire trucks and he said that the botched job they did sounds like it probably has a bad cat and they didn't want to replace it probably due to economic reasons. I have gone ahead and ordered the entire piece that includes from the header to include the catalytic converter. I wish I would have seen that oem style sensor mount before hand. I probably would have just gotten that with a new cat. Oh well, at least this way there is no doubt that everything is fixed. Found a local shop that will do the job $100. I'll post some pics when it's all done. Thanks again for all the advice and help.

 

Problems continue..... So this morning at the muffler shop I realize that the part sold to me does not fit the truck. It seems fishy because everything that I have researched says I have the right one. It's not even close. Not in size, bends, nor how it attaches to the exhaust manifold. So I have ordered a weld-in o2 sensor mount and I'm going to get a universal catalytic and muffler cause that's shot too. I tried to go oem but whatever the previous owner has done has made that impossible. Stay tuned.

 

what one did you order?

 

Is there a difference between the California and Federal Emissions on this engine I know the 3.4 is different

The federal Emission pipes will not fit because of the two cats

 

I ordered 641187. It shows in every website that I have checked to be a direct fit. The mount to the exhaust manifold is completely different as well as the lengths and curve.

 

That part number is for the direct fit cat pipe for dual cat systems. You more than likely have the single cat. Where the y pipe is built into the down pipe you need.

 

As you have determined, a previous owner probably botched up your exhaust system trying to bandaid the symptom, rather than fix the root cause.

The Air / Fuel Ratio is a wideband sensor located before the catalytic converter and is much more accurate, than the Oxygen sensor. It provides more feedback to the ECM, so the computer can accurately adjust the mixture for the engine to run cleaner. The O2 is a narrowband sensor, located after the catalytic converter and they should not be interchanged.

 

Earlier years (pre 2000 i believe) still used the same o2 downstream and upstream.

 

Ah .. uses the same sensor, just different length wiring harness?
Still different part numbers, yes?

 

not sure. ive seen on here the upstream connector on some trucks are way on top of the tranny (maybe these are just the wideband years?). on my 96 3.4 and another 2.7 ive seen the o2 connector is down by the exhaust so both o2s are identical.