P0401 1998 Ford F150 -

Question

I have a 1998 Ford F150 4.6 liter engine in it to start with had misfire on cylinders 4 and 8 and code PO 401 changed plugs wire coils and codes kept coming back after driving the pick up for 30 or more miles. Took the throttle body off and clean the EGR ports out and replaced the gaskets. The owner drove the pick up for more then 100 miles and I talked to him yesterday and the check engine light is back on and it shows the following codes PO 401 and PO 430 I have never seen anything like this before. Can you advise me on what to try this time? The pick up has 200,000 miles on it.

Answer 1

Sometimes cleaning the egr is not enough and may need to be replaced. Did you also need the EGR tube? 

I would double check for the intake/vacuum hoses