service engine soon light?

[dshiner]

I have a 1997 328IC and was just wondering if anyone knows what the fault codes of P1421 and 1423 mean for the OBD2? Or possibly where I could find the answer. I have searched a few internet sites but apparently these codes are manufacturer specific. I really dont feel like droping a couple hundred to take it back to the dealer if I dont have to.

[Jeron]

http://www.obd-codes.com/

Another good place to look is Bentley Publishing Forums

I searched "BMW P1421 P1423" and got:
http://www.autoboardz.com/E36-P1421-P1423-codes-ftopict187655.html

There appears to be a lot of info on the web for that search.

[dshiner]

OK. Just want to let you guys know what the issue (4 months later) was so you can hopefully correct the problem before it snowballs into $$$$. And I also hate when people post a problem but never let us know what the solution was!! It's annoying!!!! The fault codes of P1421 and 1423 are for the secondary air pump. This is the vacuum cleaner-like sound that you hear when you start up your car on a cold morning(for 100 seconds). It pumps air/oxygen into the exhaust manifold via a one way secondary air pump valve. The air pump valve is opened and closed by a vacuum hose. The problem starts by the vacuum hose becoming dryrotted over time (as it is right next to the exhaust) and it begins to leak. Once it leaks so much the vacuum becomes too weak to open and shut the valve. The valve then gets stuck allowing moisture rich exhaust gas to enter into the secondary air pump which eventually builds up enough water and drowns the secondary air pump and hence the CEL. What could have cost me $.10 in preventative maintanence ended up costing me >$200. What really gets me is I noticed the dry rotted hose before hand but never gave it a second thought. Take it from me, ya'll should this replace tiny hose ASAP to prevent this in your car.