Air Filter condition
 

My air filter looks dirty on the foam side but the pleated paper side looks clean. Almost brand new. I changed my filter but did I need to? I guess the fact that the pleated side is so clean means the filter is doing a great job. I used to the old 1970's style filters where you had pleated paper on both sides and I guess that's why I thought the paper side should be dirty before changing it. Let me know what are opinions are. Thanks

Dirty foam side. Air enters here
http://i30.tinypic.com/2zphzlg.jpg

Clean pleated side. Air exits here to engine intake
http://i27.tinypic.com/4g6vrl.jpg

Doesn't look too bad. I've seen much worse. The pleated side is the clean side and should always look perfect. No dirt ever. If you are chasing a CEL 1128, 1130, changing the air filter and cleaning/replacing the MAF are a good first step. Also look for loose vacuum lines around your intake between the MAF and intake manifold.

Especially when compared to the price of Fuel these days, Filters are cheap. Not recommended that you try to pinch pennies here.

The more a filter filters, the better it can filter. But that also means the more restrictive it is. This can make your engine works harder and run leaner (since the DME compensates for the decreased air supply by also decreasing the Fuel supply).

In the end, this ain't the best for the motor and also negatively affects MPG. It doesn't take too much extra Fuel cost to pay for the Filter.

My recommendation is to change it sooner rather than later.