Lean codes and engine misfires. Need help
I just purchased a 97 tbird V8. The car has 78k miles and it's in good shape. However I'm currently having some issues. The car is giving four codes:
P0174 - Bank 2 System too lean
P0171 - Bank 1 System too lean
P0430 - Catalyst system efficiency below threshold Bank 2
P0141 - Oxygen Sensor heater circuit Bank 1 Sensor 2
The car idles smooth, but immediately misses once you quickly accelerate, seems like its firing on 6 cylinders not 8, struggles getting up to speed. It feels like it loses half the power it should have. Now if you ease into it, its not bad. It does have an exhaust leak, I hear it when I accelerate.
Now I have checked the MAF, looks new, not dirty, hooked up the vacuum gauge, thats perfect. Fuel pressure is where its supposed to be as well.
The one thing I did notice was when I used my timing light. I checked all the spark plug cables with it. Some throw multiple sparks fast at idle, others throw a normal spark at idle and some don't throw any spark when I accelerate. Has anyone had that issue before? Could this mean bad coil packs or a bad ecm?
Here is what I wrote down for the coil signals:
1/2/4 regular pattern
3 regular pattern, but quits when I accelerate
6 is ok somewhat
5 fast pattern/intermittent slow pattern
7/8 fast pattern
This tells me that too much spark is leaning out the system and the ones with slow to no spark is giving the miss.
Any input would be appreciated, thank you.
1997 Thunderbird LX V8 - Sport Package