I have 03 2500 5.7.Replaced 02 with Bosch and have had problems the last month with rough idle and engine light reading low voltage at 02 sensor. Cleaned throttle body tried to replace TPS sensor, but it does not have one.
My exhuast appears to be different as well. Should have 4 02 sensors. I only have 2. Dealer mechanic said he never saw a stock exhuast like it.
Any ideas?

 

Chrysler anything's seem to all have a problem with Bosch sensors.

I know for a fact at least all the early '03 Hemi trucks be they 1500 or 2500s had a single cat - therefore only two sensors. I thought it was all the '03s for a while but I know more than a few claim to have two cats/four sensors.

Sounds to me like your dealer's mechanic needs to find a new job...

 

i replaced my front O2s with Bosch from Autozone @ $25 each a few months back and have had no issues.

 

You know it's funny you say that because this forum is full of guys who have had problems with Bosch sensors.
I replaced the ones on my Grand Cherokee with Bosch O2s from Advance and have had no problem for a couple of years, but the Jeep forums are full of posts about how they don't work on Jeep products either.

Weird...

 

As far as needing 4 O2 sensors, isn't that for a California emission setup?

 

I replaced my passenger side one with a Bosch one and am having the same problem and code that says low voltage. They read the code again and said it was something else. When my check engine light comes back on, I will have them read it again to make sure that is it. I will try to return it then. What is a good sensor to buy?

 

Mopar

 

well dammit Hammer dont jinx me because if i need OEM O2s i might have to visit the dealership late one night

 

I've always used Bosch O2 sensors. They make the Ford OEM sensors. Never had an issue with them. I will never use their plugs again though. Junk!!! Lost an engine to a crappy Bosch platinum that fell apart and ruined a cylinder wall in a perfectly good 5.0L in my dad's 89 F150. Platinum is very hard and when lodged between the piston and cylinder wall, it makes a nice deep ugly gouge.

 

and at one time I had a Consumer Reports Test on plugs that rated the Bosch Platinum as THE best spark plug on the market. Go figure???

My ex's two Grand Cherokees that had the 4.0 I6 loved them, I saw an instant 1.5-2 mpg gain when switching to them. The last GC she had while we were still hitched was a 4.7 and it HATED them...