What causes P0172 – Fuel Trim too Rich (Bank 1)[2004 Chevy Trailblazer]?
Need to know what bank 1 means. A: Basically this means that an oxygen sensor in bank 1 detected a rich condition (too little oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1. Code P0172 may mean that one or more of the following has happened: -The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of “oiled” air filters can cause the MAF to become dirty if the filter is over-oiled -There could be a vacuum leak. -There could be a fuel pressure or delivery problem Some possible solutions are -Inspect all vacuum and PCV hoses, replace if necessary -Clean the MAF sensor. Consult your service manual for it’s location if you need help. I find it’s best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it’s dry before reinstalling -Inspect fuel lines for cracks, leaks, or pinches Check the fuel pressure at the fuel rail Check the fuel injecto
