Okay so here's the deal I bought a 1996 ram 1500 4x4 with 180.000 miles on it the motor and tranny are both solid just needed a tune up and she runs like a champ now the only issue in having is I can't get it to pass smog to finish the registration battle with Dmv. I took it to smog before I had a tune up and I failed the first time for high HC at idle but passed at 2500 all other readings were good across the board the limit here in ca is Max HC 100 I Ran 133 ..i went home changed plugs oil oil filter bought a new air filter and ran Lucas injector cleaner through and ran the **** out of it on the way to the 2nd smog.. Now I failed again at 143 HC at idle but still passed 2500rpm test ..the smog tech told me he is certain its the catalytic converter and im kinda convinced too but I thought to replace the 02 sensors and have it tested for a 3rd time to see if I will pass this time but now as I'm looking I'm confused because the location of the 02 sensors are not where the guy at the auto parts store told me there is a left side sensor and a right side sensor .....i looked and the upstream sensor is on the catalytic converter on the left side and the downstream sensor is on the pipe a lil ways from the cat and its on the left side as well and im just wondering if this is right do any of you have a different setup also the arrow on my muffler is pointing towards the front of the cab shouldn't it be facing towards the rear and could that be why I can't pass smog any help would be great thank you

 

the were 2 different emissions setups - 49 state Federal and good ole California. Federal has 1 cat and 2 O2 sensors (1 upstream and 1 downstream). Cali has 2 cats and 4 O2 sensors. (1 up, 1 down on each side).

the arrow sounds backwards, but i doubt that it's affecting your emissions.

 

What dh said, but consider whether your truck is a CA truck to begin with. Mines a Fed truck and I'm in CA.

A quick test could be to just unscrews the front O2 and tie it out of the way. I'd say to make sure it is undamaged but you are replacing anyways with new. Note that some people don't get good feedback using Bosch sensors. NGK or Denso are more recommended, but typically no box autoparts store has them. Rock Auto is a good source.

Then go drive and see if you notice anything. If you notice that it drives with some pep, yes it will be loud, then it's a more sure sign the cat is clogged. Additionally, the source of it being clogged is a telltale sign that intake plenum gasket has failed. More to check to be sure, but start there.

Also, did you pick a smog station where you only pay if you pass?

What size tires do you have?

I'd suggest getting some seafoam run in there too.

Where you at up there btw? (if you don't mind) I'm in Sac region.

 

so your telling me that the cat thats on the truck is wrong and that there should be 2 cats on the truck its a single back exhaust and there's only setup with stock muffler and it has one cat two sensors one upstream one downstream
and im thinking that the muffler was installed wrong for sure

and I went to a smog station that failed me twice and charged me both times and he is convinced that its the cat but I have my doubts mechanics and all

 

and whitenuckle i live in calaveras county

 

does anybody else know if this is true I dont think its mandatory to have to have two converters in ca??

 

Autoparts store people sometimes are not that astute as they only go by year/make/model/etc. dh pointed out that there are 2 different setups, Fed and CA. The autoparts store should have asked you that question or they assumed it was CA. Only CA would state left and right banks.

I think that sucks bunk to pay 2x and not pass. Find a station that is pay only if you pass. We've got a good few up here... lol

Do the sensor test I mentioned as a way to see if the smog tech's suggestion is reasonable. As for the muffler, I can't say. Did you just buy this truck recently? If so, the seller is responsible for passing smog. Or are you selling? LOL

 

It's only mandatory if the truck was originally equipped as CA emissions.

As I said in my first reply, I have a Fed truck while living here in CA and it's legal. This truck was brought from CO.

 

yea well I kind of got screwed all together on the whole smog end of the deal and well when I went in to the smog shop he didn't say anything about having only one cat and he would of passed it if the numbers were right which makes me think if I just go ahead and replace the 02 sensors and fix the muffler back around and test the cat would I be in the clear...also my upstream o2 and downstream02 sensor are both on the left side of the exhaust is that right the guyvat kragens told me one should be on left side of cat and other on right side of exhaust but like you said those guys can be pretty oblivious sometimes just trying to get your guys input

 

I have a 2000 1500 4x4 that came from California, it is a 49 state federal emissions truck with one cat and two 02 sensors. If your truck is set up this way, then its correct.

If your truck still has the original 02 sensors, they are long past needing to be replaced, and the original cat is also probably bad with 180.000 miles on it.

If your truck is in need of a tune up and you took it in to be smog checked that way, then of course it will fail. Do a complete tune up, cap/rotor, spark plugs, plug wires, air filter, and replace the 02 sensors.

Once your done with that run some sea foam through the engine to clean out any carbon build up. Do this a couple of times and you should pass smog.