Hi Guys. I'm just looking for any ideas you might have on where to start on this one. It's a '98 1500 4X4 with the 5.9. When I start up and take off, it will idle rough, have little power. When I accelerate, it bogs down and backfires through the exhaust. After a short while like that (maybe 20 seconds maximum, it will surge to full power and runs normal as long as I continue to drive. If I shut down then start back up right away it still runs normal. If I shut down and leave it for maybe 15 minutes, it starts the whole process over again.

Thanks for any suggestions you might have.

 

Something isn't doing something properly until it warms up, sounds like.

 

is it throwing a check engine light

 

I'm guessing here, but maybe bad IAC? Maybe it sticks wide open until it warms up, then begins to operate. CEL code will be a very important and most efficient place to start, though.

 

Thanks for the advise. I checked the code and got a P0133 O2 sensor slow response bank1 sensor 1. Of course the O2 seems suspect but I wonder if it could have to do with the cold air intake. I think there may be a bad seal where it attaches to the top of the TB. I guess it would be easy to check. Does that idea make any sense?

 

I just looked at the exhaust. I only see 2 O2 sensors. One forward and one aft of the cat. I tried to trace the wires from the O2 sensor forward the cat to the connector. It seems that the connector is above the transmission in an almost inaccessible. Does that sound right? Does anyone have a secret trick for getting at that connector that I missed?

Thanks.

 

does anyone know if there are O2 sensors at the manifolds? How many are there total?

Thanks.

 

For your truck, I would think there was only 2 sensors, 1 pre-cat and 1 post-cat. Hopefully someone else who actually knows for sure will chime in.

I just searched through the service manual and saw that you could possibly have 4 - O2 sensors. If you have 4, then they are located on the exhaust downpipes ahead of each small CAT and then again just after each small CAT. If you only have the 2 sensors, then one would be ahead of the only CAT you have, and the other just after it. The only options it shows, that I can see, is either 2 sensors or 4, that's it. Hope this helps.

 

Thanks for the response.

I checked my repair manual. It says some models will have 2 and some models will have 4. It talks about the ones with 4 sensors having them before and after the mini cats. It says the ones with 2 sensors will have one on each of the downpipes.

After taking a careful look at my system, it appears to be more like the one you described. There seems to be a sensor just at the front and one at the back of a cat. There only seems to be one cat.

I know that a p0133 could have more solutions that replacing an o2 sensor. I just wonder if o2 bank 1 sensor 1 is the sensor at the front of the cat.

I did take a look at the air filter box where it attaches to the top of the throttle body. I am not sure that clamp was in place properly. I have to say the way they attach that air cleaner box to the top of the TB is a real piece of crap. I think I finally got it on right at least. I will try to drive it and see if that makes any difference.

 

The one in front of the cat is the one you need to replace, But you need to check yourself/or have some one check the cat itself also. Do you know if the CC has ever been replaced? If not, it's probably no good.