My 2008 is showing PO171 (lean condition in bank 1) & PO174 (lean condition in bank 2). Where should I start troubleshooting this? Could it be a sensor or something worse?

 

Sounds like a vac leak to me.

 

Google is sometimes your friend. Since you have lean codes for both engine banks it's not likely to be the O2 sensors. Start with the easy items - clean the MAF sensor and throttle body. Then go through every connection on the air intake to make sure something hasn't come loose. Then start looking for a vacuum leak.

https://www.700r4transmissionhq.com/...hevy-corvette/

 

check all hose/vacuum connections. Check intake clamps, etc. Check to make sure intake manifold bolts are tight. Check exhaust manifold gaskets.

Likely a leak somewhere.

 

Run your car at 3000 RPM…if your short term fuel trims go negative and your long term fuel trims gradually decrease you have a vacuum leak…if fuel trims increase you have a MAF or fuel delivery issue.

 

How do I gauge my short and long term fuel trims?

 

 

Will this scanner allow me to do that?.....
https://www.newegg.com/p/0JZ-0119-00...SIBFASJ4H4473#

 

Yes…if not a vacuum leak and fuel trims increase under load can be fuel delivery or MAF issue…diagnostics 101…for a few hundred more you can get this bidirectional which is $100.00 off.

 

Sorry for the ignorance, but what can I do with the bidirectional tool? I get that it can send data to the car instead of just received it, but what exactly can it do to my Vette that makes it worth almost $300 more than the other one? Thanks for you help btw

 

With a bidirectional scan tool you can look at most inputs and outputs and turn on (an output) the cooling fan, fuel pump, HVAC blower motor etc...as far as inputs you can see if you push a button or turn on a switch (an input) that that particular computer module is seeing it being turned on...now if you just want to read codes and look at some "live data" your cheaper one will work...that's up to you !!...it will only read Engine, ABS, SRS (Airbag), Transmission trouble codes...the more expensive scan tool will read all modules....what I find funny is guys will spend $10,000 to "bling" up their engine compartment but have a $30.00 code reader and expect to diagnosis something a little more involved with their car...it ain't gonna happen !!!

 

Have you ever used the bidirectional Bluetooth scanners? They are only $60-70 but you usually get what you pay for.

 

Never heard of a $60-70 dollar bidirectional scan tool…the VXDIAG is a little over $100.00 but the software is glitchy and it may contain malware…I’ll pass !!…I use 5 plus a strictly diagnostic scan tool…4 are bidirectional plus the Tech 2 which is not…these range from 1K to 5K.

 

Damn you are legit! Those are awesome! I bought one of those Snap-on at a pawn shop and turned around and almost tripled my money. It was basically a Windows tablet pc with a ton of features. Here's the one I was talking about. Let me know what you think, if it is worth the time try.
https://a.co/d/hgrEzmD

 

If anything stick with your first choice.

 

Looks like you have been given a lot of great advice. Since i experienced the same issue not long ago with my 2008, I wanted to share the steps taken to track it down. As stated by others since you have both bank error messages, it is likely not the 02 sensors.

I started with cleaning the MAF sensor and when that did not work replacing the sensor itself. Still no dice. Then I tightened all fasteners from intake to throttle body as well as intake manifold bolts. When that still did not work, I prepared to swap the air filter.

This required removing the hose connecting throttle body to Intake. When I removed the metal hose clamps, i noticed that the placement of the clamps were not lined up correctly with the rubber tabs in the hose. They were close but not exactly lined up.

Once I lined the tabs with the slots in the hose clamps and started to tighten, I noticed how there was a distinct stopping point where you could feel that it could not be tightened any more (i.e. felt the metal through the rubber hose). Previously, when tightening the clamps, I did not feel that same level of tightness. Although it seems pretty basic, that appears to be the one step that resolved the issue. Recommend starting with that first. Make sure the rubber nipple on the passenger side of the intake hose is pushed in all the way too. These cars do not have PCV valves.

Hope that works out. The only other step I took the same time was to add some tape to the plastic pieces under the air filter cover which seemed to have separated (one of the tabs missing). I taped the two pieces together so there was no gap. I still think it was the hose clamp though.

 

I had the same issue in my 2007. The culprit was a vacuum brake booster that failed internally, causing a large vacuum leak. As there is only one vacuum line from the intake, it was easy to diagnose by clamping the brake booster vacuum line and watching the fuel trim numbers settle down. The other indicator was the brake pedal was very hard immediately after engine shutdown.