What do the check engine light codes P1128 and P1130 on a 2000 Porsche Boxster mean?

Answer 1

The OBDII engine codes generally have the same meaning regardless of which car you have. So, a code P1128 on a Porsche will have the same meaning (generally) on a VW Bug, for example.

------------ Code P1128 ---------------- This code is usually present if your engine is running in a "Lean" air/fuel mixture situation. This code may be present as a secondary code to your P1130 code which indicates a bad air/fuel sensor (see below). My suggestion is to fix code P1130 first (bad air/fuel sensor) and then see if code P1128 goes away. If not, consider the following as possible causes of P1128....

(1) any unmetered air introduced into the engine can cause P1128 to set. Tips: Carefully check for vacuum leaks. Include all areas that might introduce unmetered air to the engine. Don't forget exhaust leaks before the O2 sensors.

(2) In some cases, this may also indicate a bad O2 sensor (Oxygen sensor). Cars usually have more than one O2 sensor and you should be getting an additional trouble code specifically indicating a bad 02 sensor. If not, then your O2 sensor is probably okay.

(3) In some cases, a Mass Air Flow sensor may also cause this trouble code, but again, there should be an additional trouble code specifically indicating that you have a bad MAF sensor

Other things to check...

(A) Check and verify that fuel pressure is in specification. (B) If vacuum leak and fuel pressure checks are normal, check the air flow signal from the MAF sensor using a scan tool.

--------- Code P1130 -----------

Air fuel sensor (common problem!). You probably need a new air fuel sensor.