o2 sensor question

[bpeters5814]

Originally Posted by Boog

You said
"It sets off the sensor after I've been driving for awhile, but as soon as I decelerate, it goes off. Makes the truck run a little rough at start-up, but other than that, it doesn't cause any problems."

Confusing. SES comes on after you've been driving a while but goes out when you decelerate and makes the truck run rough at start up?

Have you pulled the stored codes from it?
You may have a couple of different problems here.
Rough running on startup can be the coolant temp sensor. Cheap fix. The other can be egr related but really need to read the stored codes in it.
Are the front two 02 sensors in place?

I haven't checked the codes lately, but last time I did, it was an O2 code. The PO had welded a bung on one of the pipes where it would've been had there been a cat. Replaced that O2 sensor and fixed it for about a day, then went back to doing the same old thing. I've still been getting 13-14 mpg with 4.10s, so I have just left it alone. If I'm driving 55-60 for an extended period of time, SES light will come on, but as soon as I slow down, such as turning the corner to take the gravel road home from the highway, the light goes off. It doesn't always run rough at start-up. It's starts fine, but sometimes when I put it in reverse to back out of the garage, it tries to die. I haven't checked the front O2 sensors. Maybe tomorrow I'll get the trusty old paper clip out and read the codes again.