hello everyone.

I have a 1997 dodge ram 1500 with the 318. The truck itself has 189k on it but the engine is only 40k old. A few weeks ago I went to haveit smogged, and it failed. So after multiple retry attempts I was able to get it to pass. I replaced the plugs, wires, cap, rotor, PCV valve, cleaned the K&N air filter, and replaced the front 02 sensor. I know the cat is going bad, so i unbolted the o2 and loosened the flanges to relieve the pressure thinking that was the issue but it did nothing to help,but heres my problem. When I put it under load at all, it falls flat on its face. I can have the pedal buried and itll only do like 20 mph, and then try and die. When I had my data logger hooked to it I was getting very lean fuel trips and multiple misfires on 2,4,5,3,7,6, and the check engine light flashes as well.when I bring it back to an idle it tries to die but picks itself back up right before it does.I also hear a very loud hissing that gets louder with more throttle and it sounds like its coming from the pass side when I crawl under the truck, but I cant seem to find where its located. My best guess is around the back of the header.

what I am wondering, is could this be a fuel problem. Its the original pump and I know these trucks dont have a filter thats replacable. ANY help would be much appreciated as I drive this truck to work daily.

Thanks for your time,
Andy

 

dude that sounds like a clogged cat.. with it hissing and all...LOL..maybe a **** off cat.... but serious i would have that cat check asap.. or maybe the muffler....

 

I was thinking that it may be the cat but would a plugged cat cause it to run liek crap evenm if i loosened the flanges? The hiss is coming from the cat area, but its getting worse and worse by day liek I can hear the engine struggling.

 

I just banged on my cat with a wrench, I can hear sounds of stuff inside moving around. Cuuld a plugged cat really affect it this bad? because even when I had the 02 sensor out and the flanges loosened it still ran crappy but much better than with everything bolted up.

 

YES!! My truck did the same thing but i thought it was the tranny till it stalled and had it towed to a shop, cat was totally shot.

 

I am having similiar problems, not that severe, but the hissing thing yes along with rough idle. I changed the IAC and it's got about 30 miles on it and did affect it, but still isn't solved yet. Therefore I'm joining in saying it might be the cat, which was my first assumption.

 

lol thats funny that you mentioned the tranny, because I too was wondering about the tranny, thinking maybe it was stuck in 2 gears or what not, but even if it was it should have still been ok in neutral. My trannys ok, but it still slips a bit in 4th, like 300rpm's up and down. Any thoughts? I had a friend recommend a trans go shift kit for the valve body, any experience on that?

 

i know that if you have your air cleaner off and with it running it will run very rough like its straining for air- in which its actually getting too much air- it makes a hissing sound and rough idle and if you hit the gas it shuts off. Try looking and see if a vaccum line is off somewhere or if your air cleaner is on all the way. Definately sounds like and air/fuel ration issue just from past experience- BUT not a pro just makin a sugestion

 

dont ignore that cat... can lead to very bad things if not fixed. get it fixed then report back to us. all that backpressure ofa plugged cat and reak havoc on your valves and other things.