P0172 & P0174, rough idle after timing chain replacement

[vw06gti]

Looking for some insight on things to check or tell the mechanic,

I recently had the engine pulled and timing chains and guides replaced on my 2001 Sport Trac. The truck is driving ok at road speed but idles rough once i put it into gear.

Pulled the following codes:
P0174 System Too Lean - Bank No. 2.

P0172 System Too Rich - Bank No. 1.

I brought it to another mechanic who checked the sensors is they are reading correct bank 1 is rich and bank 2 is lean, he also showed me that there is a weird noise when you try to fire up the engine with coil off that he says don't sound normal. He didn't do a compression test but he thinks that the timing might be off possibly on the drivers side. Also he did a vacuum test and everything looked good. Its just weird because the truck runs fine while driving it.

I am going to bring it back to the shop that did the chains, wanted to give them some ideas on what to check before I did.

 

[rickybobby]

I wouldnt mention anything to the shop that did the original work except the code numbers and the fact that they werent there before the work. it is always good to be armed with a second opinion and plenty of information, but some shops get a hair up their butt if they know you got a 2nd opinion, especially if you are having another shop second guess their work.

 

[2000StreetRod]

Pre-cat O2 sensors reversed?

I think the most common cause for one bank rich and the other bank lean is when the pre-catalytic O2 sensors are connected incorrectly - bank 1 wiring connected to bank 2 sensor and bank 2 wiring connected to bank 1 sensor. Passenger (right) side is bank 1 because it connects cylinder #1. Driver (left) side is bank 2. An easy check is to disconnect the bank 2 sensor and see if the PCM reports O2 heater sensor failure for bank 2.

 

[vw06gti]

I think the most common cause for one bank rich and the other bank lean is when the pre-catalytic O2 sensors are connected incorrectly - bank 1 wiring connected to bank 2 sensor and bank 2 wiring connected to bank 1 sensor. Passenger (right) side is bank 1 because it connects cylinder #1. Driver (left) side is bank 2. An easy check is to disconnect the bank 2 sensor and see if the PCM reports O2 heater sensor failure for bank 2.

So you saying that this these sensors could be switched on the chassis connectors

 

[vw06gti]

Do you know where I can look for these connectors, or any have a picture.

 

[2000StreetRod]

between block & firewall?

I don't know about the Sport Trac but on my Sport the connectors are between the rear of the block and the firewall.