When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Just had my transmission pulled and totally rebuilt and upgraded last week and while they had the tranny out, I asked if they would change my Oxygen Sensor. I bought a Bosch O2 sensor and they replaced it for me. My truck was done and I drove it home (15 miles) and right before I pulled in the driveway my engine light came on. I took it back to the Transmission Shop for them to work on. They ran a code reader on the engine and tranny and it came up with Code 41 (Lean Left Bank, EGO not switching). They ran the Code Reader before they worked on it and nothing came up (No Codes in Memory). I found out that the O2 Sensor was bad. They replaced it and I was on my way. After driving 5 miles the engine light came on again. I took it back and it was reading another Code 41. We checked to see that the O2 sensor was plugged in and no wires were damaged. I am thinking it might be a bad MAP sensor? I can't believe that another new O2 sensor went bad. Anyone out there had this problem?
O2 sensors tend to be pretty reliable. I had a similar problem which turned out to be a bad EGR valve. I pulled the EGR valve and found that it was stuck. After freeing I still got the 41 code. Took off the EGR valve again and found it would not hold vacuum. Replaced it (CA part - $95 - ouch!!) and problem went away. Worth checking. Good Luck.
FL Panhandle
O2 sensors tend to be pretty reliable. I had a similar problem which turned out to be a bad EGR valve. I pulled the EGR valve and found that it was stuck. After freeing I still got the 41 code. Took off the EGR valve again and found it would not hold vacuum. Replaced it (CA part - $95 - ouch!!) and problem went away. Worth checking. Good Luck.
FL Panhandle
Good info! Thanks.
Have you changed the egr valve AND egr valve position sensor or just the egr hard metal part? Thanks!
Good voltage on o2s. Still getting 41 code when ildling. What else could it be?
Im having 41 code when driving slow or parked ildling. I can be driving down the highway for hours and nothing, as soon as I pull over and manuver or park light comes on and stays on. Its always 41 code. Measured voltage on hego, reading 500-600 millivolts, which is perfect or close to it right? Also, sensor wire does get the 12 volt feed.
im thinking if it was the wiring issue the light would always stay on correct?
Im attaching pictures of my scanner. It lists all possible causes of 41 code particular for 460 big blocks with e4od.
It even includes that transmission can trigger that code and there is a tbs on that as well. I tried searching online, no info on that tbs. See the pics attached.
The first 2 show a ground error and from what I have seen posted a bad ground could cause all kinds of issues.
I want to say I have seen posts where the PCM ground is by the battery and because of the off gassing of the battery that ground goes belly up.
I would check it and all grounds, battery to motor & frame, motor to firewall and any grounds by the battery to the fender.
I know the head & turn / side lights have grounds by the fender / radiator support on each side.
Dave ----
02-05-2001, 12:06 AM
