Hello I'm doing long tube headers on my 2003 ram 1500 with the Hemi. When I bought the truck the cats were already cut out and true duals already put in just off the stock manifolds but it's literally rat **** so I'm redoing it plus the manifold bolts were broken and one manifold was cracked.

I noticed it's only got 2 oxygen sensors and they were just in the one pipe is this normal for 2003 to only have 2 oxygen sensors? My 2004 and 2005 have 4 also if it's only two do I have to merge the pipes for the sensors? Or can I add another set of sensors somehow? I'd like to hear from the guys that have done this before and what you guys did.

 

Are you getting a check engine lite whining about O2 sensors? If not, then likely yours only came with two.

What engine in your truck?

 

🤦🤦🤦🤦🤦

 

You asked to hear from people who have done this before, I have not but suspect not many others have either.
You should have an O2 sensor upstream and downstream of each catalytic converter. Your truck came from the factory with two cats. It sounds like someone modified your exhaust to have a cat on one side of the engine, and no cat on the other. Your engine is being metered based on the inputs from the cat side of the exhaust.
You mention merging the pipes for the sensor. If you do that then you do not have a dual exhaust.
Does your truck get safety inspected every year? If so, I rec asking an inspector what is required to pass exhaust emissions inspection.

 

Ok so my 2003 does Infact come from factory with two cats? Someone has definitely modified the exhaust because since I've owned it there never was any catalytic converters and it already had duals and only two oxygen sensors on the passenger side and I can't seem to find the pigtails or any cut or tied up wiring for the other two on the driver side. Threw me off a bit 😂 someone else mentioned that it might have only one cat and two 02 sensors to begin with

I suppose asking for someone with experience here with this specific thing isn't the right question I should be asking all the 2003 ram Hemi guys to show me their factory exhaust 02 sensor locations and cats

Is it safe to just put the sensors in one pipe and call it a day?

 

That's exactly what the manufacturers did for quite some time.

 

I think it is safe to put O2 sensors on one side, just check a couple of spark plugs on each side every few months to see if you have a rich or lean condition. My guess is the side with the cat and O2 sensors will be fine, the other side would be the one to check on.

 

2003's only had one cat.

 

Thanks boys this is exactly what I needed

 

My 2002 also has only one cat, one upstream, and one downstream O2 sensor going down the passenger side. Think it was an 02-03 setup only. Parts stores always say I have two cats and 4 O2 sensors when I inquire about an O2 sensor, but they're wrong. Dealer goes by the vin when I call them to look up an O2 sensor and their system comes up with the correct single cat two o2 sensor setup.

I prefer this setup, only one cat and less O2 sensors to change if needed.