When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I bought an OBD-II compliant setup (OBDII Automotive Scan Tool and Virtual Dashboard) that runs off a laptop - it does real-time recording of a number of different parameters ( temp, O2 sensors, etc.) - its worked really well for me, and was pretty inexpensive (comparatively). Software is updated regularly, help is really good, and you can trade the thing in towards a new one if you change cars.
I just bought a Digital OBD2 at Kragen auto on sale for $99. Found that I had a P0401 "EGR flow insufficient detected" Reset it. Do you know what causes that?
Only code I ever got that was 'EGR' related turned out to be DPFE instead of the EGR valve itself - apparantly a fairly common problem in rangers from what I was told. But sorry I looked but couldnt find the code.
Differential pressure feedback EGR (DPFE) sensor measures the amount of flow through through the EGR valve. Sorry dont know much more than that. On my truck, very easy to replace near the top of the EGR valve held to engine with two screws, two tubes come out of it.