Idle
Upstream O2 Sensors

Bank 1 Range .060- .790
Bank 2 Range .070- .760

Downstream O2 Sensors

Bank 1 Range .075- .765
Bank 2 Range .725- .730

Are these voltage readings good?

Note: I performed the Seafoam intake procedure and noticed white smoke (size of a cigarette puff) coming out of both sides where the manifold connects to the 'Y'. I have been periodically getting Codes 1141 & 1171.

Thanks-

 

The Bosch ECU manual is online in my signature as part of the tech manuals, it is under Engine manuals. In it the O2 and catalysts voltage ranges and codes are given, plus basics on what they are doing. If they are changing it is usually a good sign.

And SeaFoam found a small exhaust leak for you.

 

The readings are changing while it's idling. Would a small exhaust leak trigger those Codes 1141 & 1171? I downloaded the RAVE and looked at the Code list and the voltage info. but I've got to be honest. Just not great at understanding all of that technical data.

My initial thoughts were the codes are random when I am at a long stop light and the temp goes from 188F to 199F with the outside temperature in the high 80's or low 90's. It idles a little rougher and every now and then the check engine light turns on posting those two codes. Checked for all vacuum leaks and attempted the smoke test. Did not see any smoke only until I did the Seafoam treatment.

Thanks-

 

1171 is one bank running lean. Can be dirty air filter, MAF needs cleaning, any kind of vac leak from loose or cracked hose. You need to fix exhaust leaks also.

 

I will check the air filter and recheck all if the connections again. Can I clean the MAF on an 03'?

 

If you use made for MAF spray and do it when the ignition key has not been in the truck and engine is cold. Turning the key on heats up the sensor inside.

 

Bank 1 will go between 0 and 1 volts. They must be warm to do ths.
So drive around, then park and check them out.

The downstream - they don't oscallate. Down stream will have about .35 volts when you are pushing up a hill nad that's how I measure those. When the engine has full output or a good load on it.

Most important up steam must oscillate.

 

To answer your question regarding your white smoke and can those leaks in front of the cats cause bad readings or fault codes, "YES".
I would repair the exhaust leaks prior to cleaning the MAF, which can be a little touchy.