2004 Dodge Dakota 4.7L P0175 Code: Rich Mix, Misfire, and Engine Idle Issues
I own a 2004 Dodge Dakota 2WD with a 4.7L V8 engine. Recently, the vehicle started throwing a random multiple misfire code (P0300), followed by a P0175 code indicating a rich fuel mixture on Bank 2. I replaced all eight spark plugs and cleaned the MAF sensor, also swapped out the air filter. The engine starts fine at idle—initially running smoothly around 800–900 RPM—but drops to about 600 RPM and runs roughly when driving, with noticeable power loss. After replacing the plugs, I noticed that cylinders 1 and 8 had blackened spark plugs, which led me to suspect faulty fuel injectors. Is this a reasonable diagnosis? I’ve also observed intermittent P0172 (rich mixture on Bank 1) codes, though they appear less frequently. The exhaust manifold connection for Bank 2 was previously loose but has been tightened several months ago. Any insights into potential causes—especially related to the O2 sensors, fuel pressure, or engine mechanical wear? I’m considering replacing the injectors on cylinders 1 and 8, but want to confirm if there are other more likely root causes before investing in parts.
Also note that P0172 has appeared once or twice alongside the P0300 code. This suggests a potential lean/rich imbalance across both banks.