Question for the code experts

The basic meaning of each code can probably be checked by looking at the other threads referring to them - try putting one at a time into search and a vast wealth of previous advice will normally appear

 

Clear the codes and drive it around to see if they reappear. I think those last 2 were some of the same ones Ketel was throwing at my house and have to do with the smog stuff.

 

secondary air injection

Check the fuses under the passenger kick panel, there is a air pump fuse that blows a lot, think its 15 amp

When you cold start you will here a whinning sound for 2 mins, thats the air pump injecting air to get the cats warmed up fast

 

pending codes, different codes turn the cel after the computer recognizes fault conditions a preset number of times. for instance a misfire may trigger a cel after one detection, other items like a downstream 02 sensor may trigger a cel after the computer recognizes the fault after 6(or more) engine starts. they are called monitors. usually factory repair info has a monitor chart which states how many times a fault has to occur before triggering a cel . codes will stay in pending , if the fault is not recognized in the required number of start cycles , lets say breifly unplugging a temp sensor then quickly reattaching the plug, the computer generates a code, stores it in pending , then looks for the condition to reoccur . if it does not,then the computer will remove the code from pending.obd2 emission testing requires that these " monitor" conditions be met to pass an emission test, thus, you can not reset the cel right before an emission test. each monitored system has a different number of start cycles with no pending codes before the system monitor is met. some monitors such as downstream 02 systems require as many as 20 to 30 start cycles with no faults recognized before the monitor is met. most systems such as upstream 02, maf, temp sensors, are 3 start cycles with a pending code and the cel will illuminate

 

1448 is bypass valve
1451 is secondary air pump circuit.

Your bypass valve is not opening or closing as it should, or the related TCU is bad.
The secondary air pump is not turning on due to a blown fuse, I bet. Note the blown fuse may be due to a bad / stuck pump.

Good luck.

 

Isn't the bypass valve controlled by the main engine ECU? Opening is dependent on RPM and gear selection and throttle position, no?

 

The ECU sends a signal to activate a vacuum port which activates the bypass valve. Once opened, hot exhaust air goes to the other side of the valve and changes the air temperature which is picked up by a Thermocouple attached to the muffler. The thermocouple also goes to the Thermocouple Control Unit which is attached to the wiring harness back to the ECU completing the feedback loop.

When the valve is stuck, and the TCU does not see the exhaust temperature in the bypass valve, it throws a CEL code. If the valve works and the TCU is bad, it also throws a CEL.

 

Don't quote me but. I believe they will cause you problems. Do a search I think you are allowed 1 pending. Code only in California. If you search your state and smog it will tell you the conditions.

 

Ok. That makes sense.