[devsoul]

I am in need of some advice. My truck runs rough and is sucking massive amount of air through the IAC. It always starts and idles fine but after a few minutes it starts to run rough and sounds like there is a major vacuum leak, which goes away after another minute or two. I have changed the IAC, post converter O2 sensor and cut a section of my converter open to see if it was plugged(in which case it was completely hollow). I have just recently changed plugs(from originals to a plus four), before all this started. I originally had three codes, p0420, p1195 and p1762. Now i only get p0420 cat. effect. I also sea foamed the entire system through the brake booster line because i ran a can in my fuel one time and the problem went away.

Any advice would be greatly appreciated!

 

[atvfamly]

Hey, I seen that you said you changed the "post converter" O2 sensor. Did you mean pre converter, or was it the one after the cat? I had very similar issues and changed the O2 sensor before the cat, along with everything involved with the cooling system (coolant flush, hoses, coolant temp sensor, stat), but I'm pretty sure it was the O2 sensor that cured my problem.

 

[devsoul]

It was the one after the converter. I was getting a catalyst effect code so I thought that was the one to change.

It does seem to either be temp. or time related. It is very consistant when it happens. Also now that I am runing the A/C all the time, I can hear the IAC open and shut when driving. It also runs rough when this is happening.

I had the thought it might be my temp. sensor, but I hate chasing my tail and spending the money on things I don't need to replace.

 

[devsoul]

I drove it in to work this morning with the converter still open and had the same issue. Apparently the exhaust was not plugged.

 

[RedRam10]

Hi and a warm Carolina welcome to the best RAM ForumZ on the web. How about posting a few photos of your truck? I'd like to reccomend a solution but don't have one for you, however, I will askmthat you jump over to the Newbie Checkin and introduce yourself. See you round the site.:Hey:

 

[atvfamly]

I know what you mean, hate to spend money on something that doesn't need fixing. When i changed my pre-cat O2, it also helped my mpg. I was told that the pre-cat one monitors how rich or lean the engine is running by what it senses. With my sensor being bad, it never told the IAC (idle air controller) on the back of the throttle body to lean out as the engine warmed up, which led to me having to raise the engine speed up to about 2k on the tach until it reached operating temp and would smooth out its idle. Otherwise it would run real rough, like it had a huge cam in it, all rough and lumpy. Sounds weird, but true.

 

[atvfamly]

Maybe it has something to do with the fact that both of our trucks are 99 Ram Sports with the wonderful 5.9 in my young sons favorite color "banana"!

 

[devsoul]

Wouldn't a bad O2 sensor throw a code? The only code I get is effect catalyst effect.

 

[atvfamly]

Mine would once in a while, but sometimes be months in between throwing a code.

 

[atvfamly]

What code (number) is it throwing out?

 

[devsoul]

P0420 Catalyst Effect

 

[atvfamly]

Hmmm...........

 

[dodgeman9859L]

well guys i hate to interupt on you guys thinkin its only 99 sports but my 98 2500 has been doing that since winter. iv changed every sensor on my engine and complete tune up plus the 02 sensor before the cat. still does it. only personwhos givin me a decent idea of what it is was my brother in law who said it was a bad intake manifold gasket. not the plenum gasket that makes you burn oil. theres another gasket supposedly that does it. so thats what iv been told but im too broke to bring her to the shop for their opinion on it. so id say look there and let us all know how it turns out.

 

[devsoul]

I am taking it to a garage after work tomorrow to have my cut out welded back in the converter. I will stop and get a small methane torch, if it is a blown gasket causing a vacuum leak I should be able to find the leak with the torch(unlit of course).

 

[dodgeman9859L]

well hopefully you can get it figured out and give me some more insight on how to fix mine too. good luck.

 

[devsoul]

Problem solved, almost!

Here we go.
I took the truck and had my cut out welded back in the converter. I had an idea on my way home that since my converter was empty I didn't need the new O2 sensor I just put in. I thought I could use the plug off of the old sensor, plug it in where the front sensor goes, bare the ends, push them in the sensor plug and use the back sensor instead. Well, the plugs are different sizes. So I decided to leave the front one unplugged and see if I still had the problem. It is running good now. The computer must go into a default setting when it senses the O2 is unplugged. I sugest unplugging your O2, one at a time to see if it helps. The front one plugs together right above the transmission, the rear on the side. I am going to leave it unplugged and see how it runs for a couple of days.

If anyone knows how to post video, I will get it running bad before I replace the sensor and post it so you can tell better if this is the same problem you are having.

I also took my cap off and cleaned the rotor last night. That seemed to help it run smoother. Going to change those soon also.

Let me know if this was any help.

 

[dodgeman9859L]

well my front 02 sensor i replaced this past spring so that should be fine. possible the back one needs replacing. just cant wait to get the crap out of my cat so my exhaust flows good. hopefully everything will make it run good.

 

[devsoul]

It ran fine all the way to work this morning

 

[devsoul]

This answers the problem I was having-

http://www.justanswer.com/dodge/4qgod-dodge-ram-1500-4x4-02-1500-5-9-gas-150000-mi-runs-rough-within.html

Thanks to deanthecrabman!