PO 171 & 174 Codes (Lean Banks 1 & 2)

[thorgal]

Listen , I am not saying you have a intake manifold leak, but ..PO 171 and 174 could mean something as simple as worn O ring on dipstick or improperly inserted dipstick , also check oil plug for tightness and all the metal clamps on intake plenum chamber as well as clamp on throttle body.

 

[bmruff]

Besides the shop testing for air-related leaks, I used some starter fluid and sprayed around all the hoses etc and listened for any change in the idle. Nothing sounded odd. Also, checked the oil plug & cap. The dipstick feels very tight with no signs of damage on the O-ring.

Also, checked all the clamps around the throttle body. Not sure where the plenum chamber is?

I like the intake leak tester idea, but suspect the tests so far have ruled out any air leaks.

Any other ideas?

 

[waspjr123]

Don't use starting fluid !! You will damage your engine

 

[waspjr123]

Can u data stream the o2's and see if they are responding to change ?

 

[bmruff]

I have a Innova 3160d scanner. It has a live data function that I used to get O2 readings (previously posted). After the LR is warmed up they do change marginally. Is there another way to test them? The scanner also says O2 sensor status is "ok".

 

[waspjr123]

Well normally wot would test you but i just wanted to see if they were responding to change so you checked around the injectors hey

 

[Crosbo]

Bmruff, did you ever identify the problem?

 

[E1966]

I have the p0174 coming up, same issue as your vehicle except for the absense of p0171.

I believe its the Oxigen sensors that create that problem, one of the 4 sensors might be bad. There are 2 upstream before the cat and 2 below.

Hope this will help you.

 

[bbjj]

Im having the same freaking codes and tried everything. Lost count on leak tests.

Sent from my moto g(6) play using Tapatalk

 

[scott schmerge]

Alright, I just got bank one and two system too lean. Anyone have insights? Checking voltages on 02 sensors and they seem fine. The mass airflow sensors are showing a -30 v on bank 1 and 1.5v on bank 2. Is the bank 1 mass airflow sensor my culprit?