Engine light came on my 2011 Subaru Legacy premium. I connected the computer and got three codes. P020 PRM, P0420 PND, and P0420 CNF. Can you please let me know what they are?

Kevin Blair

• 196 Answers
• Posted on Dec 18, 2008

SOURCE: how to retreive a check engine light from a 1991 subaru

read the info in the link it has a step by step http://legacycentral.org/library/literature/codes.htm

SOURCE: Toyota Camry 2004 P0420

well that's if I'm not mistaken, catalyst system efficiency THRESHOLD!!! it is "bank" when your description code explanes bank 1 that is a O 2 sensor anything says BANK is a Oxygen sensor = O 2 sensor.what is it doing shutting off when eng warms up or sputtering or nothing really out of normal behavior? these switches will loose all communication with computer or get stuck in 1 of three ranges each range behave differently! in each range the deal with these are these switches are a part of maintenance usa @ hundred thousand km they should be change for emission efficiency and fuel consumption and vehicle performance usually after 1 is changed 9 times out of 10 shortly after the next bank will produce eng light and so on!! I usually change both while I'm at it you know pay me now or pay me again later but twice as much! well hope this helps you out good luck cheers happy new year.John, Toronto,Ontario

SOURCE: what oil for my 1995 Subaru Legacy 250T?

I know I will get some argument on this one, but regardless of what manufacturers recommend, the best possible lubricant is a good synthetic. They far exceed any manufacturers needs in both lubricity long life and resistance to thermal changes. they do not burn off or form deposits readily and work in any temperature climate. as far as rating, a 10-40 or 50 works for everything. With synthetics those #s are almost a decoration on the can because in reality they cover a far larger span. Personally I would not use mobil1 (too much additive package not enough real stuff) on the other end, amsoil is one of the best (they even offer a 0w50 oil)
Whatever you use make sure you keep it clean. A good oil filter is essential and if extending oil change intervals, you can just change filter and any oil lost.
I know I've ranted, but the actual lab testing results and notes I've made over the years is far longer!
good luck whatever you decide on!

SOURCE: 1992 Subaru Legacy Check Engine Light

There is two Green single wire plugs under the dash, driver side, above your left leg (rh drive) plug them together, engine check light will flash, www.auto-diagnostic-codes.com will help to read codes

SOURCE: Check engine light on. P0325, P0420 2000 Subaru

CODE PO420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK I * CODE PO325 KNOCK SENSOR NO.1 CIRCUIT MALFUNCTION BANK NO.1 OR SINGLE SENSOR