I got this truck recently used, it's a 97 Ram, 5.2 engine. For the money I took a gamble and purchased it, even though the check engine light was on already. I've had it for a month now, without any real problem to speak of, other than that pesky leaking moonroof I noticed a couple of mornings now when it's been pretty cold outside that it would sort of lose power for a minute or two as got about a mile or two from the house. Then it perked up and everything was fine.

I was in AutoZone today and asked them to pull the codes from the truck and see what I was dealing with. The code they gave me on the printout is HO2S11, Probable cause 1) Oxygen sensor defective, 2)Poor connection to oxygen sensor, 3) Check circuit-fuse.

And Code HO2S12 1) oxygen sensor defective, 2)Fuel system running very rich or lean, check other codes first, 3) Engine misfire condition, repair, 4) Fuel pressure very high or low, fuel pump or regulator.

Pretty straight forward for the most part, I thought. until the fella told me I had either a vacuum leak or a plugged cat.

Anyone have any experience with this? Oxygen sensor seems to be no big deal to take care of, but fuel pump is something I just don't want to tackle, it is in the tank yes? Vacuum leak, I wouldn't even begin to know where to look, I'm not completely incompetent with taking care of my own work, but close. I see many threads about basically coring out the cat and putting a dummy oxygen sensor in or cutting it out, what about banging on it with a hammer if that's the issue? I'm starting to ramble, appreciate any insight you all may have.

 

Consider replacing:

O2 Sensor (the one upstream from the Cataylic Converter)
New Plenum Pan from Hughes Engines or APS Precision
New Cataylic Converter (go for a Hi-Flo one)
New Spark Plugs
New Plug Wires
New Distributor Cap and Rotor

The plugs, O2 sensors, and cat will all be hurt by a leaky Plenum Pan. This won't be very cheap, but you could cut the cost in half or more by doing it all yourself.

 

you can do all of that within 15 hours if you know what your doing. The plenum is not as hard as everyone makes it out to be, i found it to be a breeze, but others have different opinions.

to change the dist. cap/rotor, its much easier if your doing the plenum since you have to take out the manifold.

the CAT could be replaced within a half hour if you know what your doing.

plugs and wires speak for themselves...easy stuff.


with all of that your looking at about, 500-700 if you do it all yourself.

if you bring it to a garage to have this done, then your looking at probably 2K+

 

Talked to a buddy of mine today that IS an actual mechanic, unlike me. It is the plenum that is leaking. He had me do the thing where you check for vacuum on the PVC, sure enough, vacuum where there shouldn't be any. I'm afraid there is no way I'm going to tackle this one myself, so he's going to do it for me after the holidays. The truck is in good enough shape that it seems worth putting the money into at this point. Thanks for your insight everyone! I love this place

 

Make sure to get an oil change too, since the intake manifold will be removed. Another thing you could do is buy a Hughes AirGap Intake Manifold, instead of a new Hughes or APS pan. It eliminates the plenum pan altogether. How much is he going to charge you?

 

I have no idea what he will charge me for this, he only charges me about 20/hour so I'll run it past him and see what he thinks. The engine has around 160k on it now so I don't know if it'll be worth it in the long run. The oil change is a great thought, thanks for mentioning it!

 

I put mine on at just over 160,000 miles. It works really well. I got a quote for the plenum fix, and it came out to be $400 in labor. Then he said he would put on any tuneup parts I bought for free, since he was going to take them off anyways. That was the best deal I could find, so I did it myself. Not as hard as I thought it was going to be.