No Power and Can't pinpoint the problem PLEASE HELP!!

[docraymund]

You didn't mention checking the catalytic converter. Do an exhaust backpressure test.

 

[cmlangley]

I put a pressure gauge on the upstream O2 sensors and it never reached over a pound

 

[stamp11127]

In your first post you mentioned a noise behind the throttle body. I would find out what it is and what is causing it. What type of sound are you hearing?

 

[cmlangley]

It is like a tapping, knocking noise coming from the center of the intake. I put a stethoscope on the exhaust manifolds, the heads, and each intake tube but it's only coming from the center, inside portion of the intake manifold

 

[46L281GT]

In mustang-land dorman intakes absolutely suck. They decrease the power dramatically. I doubt that's your only issue in this case, but just throwing it out there.

 

[stamp11127]

Verify the fuel trim for each bank, I think it is the stft(short term fuel trim). It will be given as voltage readings from the O2 sensor for each bank.
If they agree with the codes for that bank look at your problem logically:
1) injectors show good
2) fuel pressure within spec
3) ecm will have to be functioning in order to lean one bank and richen the other

To me it is easier to work on lean conditions first. So how can it be lean on one bank?
Air leak somewhere., usually rotted hoses or pinched gaskets. Time for carb spray - if you spray a hot egr it does light up. Ask me how I know......

 

[autoarcheologist]

Is it possible to reverse the O2 sensor wires by mistake? The fact that one bank is rich and one lean makes me think something is reversed.

Sent from my ONEPLUS A3000 using Tapatalk

 

[stamp11127]

No to reversing the wires. Voltage is produced based on the amount of oxygen in the exhaust that reacts with the sensor.

 

[cmlangley]

I checked my STFT today at 2000 RPM and my MAF was 61.96 and Spark advance was 19 any idea what would cause theses readings?

 

[cmlangley]

Found the problem, with the Dorman intake manifold my exhaust pressure never reached over 4psi and would fall as I held the engine at a higher rpm. The knock/tick I previously tried to explain and never gave a definite answer to what or where it was coming from. It was coming directly from the center of the intake manifold, yes I know there is nothing mechanical there other than the idle air control motor and it certainly wasn't that. Stumped, I decided to purchase an original Ford intake manifold and after installation there was a big difference in all engine pressures. The mass air flow reading was back to normal and idle was rough, I know that sounds like a bad thing but with the other intake I had hit a dead end. I rechecked previous exhaust pressure this time 2lbs at idle and up to 22lbs at 2000rpm. Pulled the exhaust and the cats were melted, took the truck for a ride she runs like a ***** ape. Thank you everyone.