Year: 2009
Make: Honda
Model: Pilot LX
Alternator failed on the wife's '09 Pilot. Performed repairs myself. Fuel economy plummeted from around 20 to around 13 mpg after return-to-service. Below is a list of repairs I made while car was out-of-service.
-Replace failed alternator with rebuilt alternator. (performed voltage drop testing after return-to-service)
-AC clutch bearing squealing, removed pulley and replaced bearing. (checked air gap then monitored proper engagement after return-to-service)
-Replace VVT/spool solenoid gasket with OEM Ishino Stone PN #W0133-3784975 (TSB exists about oil leaking into alternator)
-Replace PCV valve as preventative measure
-Clean terminals and charge battery before return-to-service
Something within the work I performed must be the culprit for the huge loss of fuel economy, but I'm scratching my head. after return to service the loss of fuel economy was immediate (before alternator failure around 20 mpg, after return-to-service about 13 mpg)
Car has been back in service for a few months and is reliable at the moment. Along with the fuel economy loss came a random misfire code that comes on once every few weeks. As well the ext/int lights pulse as if the regulator in the rebuilt alternator is suspect.
Any ideas what may be wrong here? Is the new alternator suspect? does the new PCV valve have a vacuum leak?
I need Scotty's help!
random misfire code that comes on once every few weeks
you need to address this. Get a per-cylinder misfire count.
See our FAQ for more info.
Have you checked live data to see if there's anything obvious out of whack?
what data points would you recommend looking at? I have a single direction autel maxicom.
The basics would be things like fuel trims, ignition timing, misfire counts, engine and transmission temperature, MAF (or MAP if so equipped) and O2 sensor output. You could probably write an encyclopedia on really getting into it which is why the really high end scan tools like the ones Scotty uses are nice since they automatically flag items that are out of normal range. If you search online for something like "analyze OBD2 live data" you'll find a lot of information on digging into the data.