Scanned my computer , came up with a PO 171 and 174 what does this mean?

SOURCE: Scanner codes

P0607 I think is An ECU problem and it may need to be replaced. I'm having the same issue. I replaced The Unit but now I'm told that the ignition switch needs to match the brain...........

SOURCE: Engine Performance problem 2002 Ford F150 V8

Hello Bret.
These codes are indicating engine misfires. 303 is cylinder #3 and 304 is cylinder #4. The 316 indicates that the misfire happened in the first 1000 revolutions.
These trucks are notorious for misfires. The most common issue is ignition coil failure. Failure on these coils can be accelerated though by spark plugs that are worn and contamination from oils, antifreeze leaks and water.
If it has been some time since you have replaced the spark plugs this may be an opportune time to do so. This job isn't for the faint of heart or those with little patience. Some of the coils and plugs are difficult to access, especially #7 and # 8. I also recommend torquing the spark plugs properly as there are some thread stripping issues on the spark plug threads with these engines.
Have at least 2 new coil assembly's for the two cylinders that are misfiring and be prepared to find at least one more that looks poor. I have used some aftermarket coils but have had issues with them. Ford has reduced the price on their coils to reflect a more fair market value so I would use those.
Have a look for any contamination issues and repair those to prevent future problems.
Hope this helps you along.

ZJ Limited

• 17989 Answers
• Posted on Sep 20, 2011

SOURCE: Hello, Engine light is on and

Both are refer at Auxiliary Emissions Controls

• P0471 Exhaust Pressure Sensor Range/Performance

• P0472 Exhaust Pressure Sensor Low