Cost and complexity depends on exactly what trouble codes you found. Post the codes and we can help. Saying that it's the pollution control system is way too broad. There are many components in the system
A GM dealer can tell you if you give him the VIN number, but the simplest way is to check one of the rear struts for an electrical connection (will also have a leveling air line connection). If there is one, you have a road sensing suspension (RSS) with rear leveling capability - if not, just air shocks. If you have RSS, these struts are very expensive and notoriously unreliable, and you may want to replace them with air shocks. However, if you do this you will have to trick the RSS into thinking they are still there by terminating each electrical connector with a resistor (see the Cadillac Forums website).
fault codes will reveal a problem ambient air temp or atmospheric pressure sensor(BARO) fault
these units report to the ECM so that the correct air/fuel ratio can be obtained
The same as pulling on the old choke
Easy to buy, difficult to replace as it is in a very awkward place on the top of the end of the transmission near the right drive axle location. Requires a hoist and the need to disconnect a few things to get at it.
I would think a sensor is going bad , but ,without testing that is just a guess , just like the dealer tech , assuming it's a module or a fuse ! With the light's on checking for DTC'S - diagnostic trouble codes would be a real good first step . The dealer tech should have hooked up the Tech 2 scan tool an checked codes an look at sensor data parameters ....
With the service engine light flashing it means there is a catayltic converter damaging misfire happening . With you not knowing about car's it may be hard for you to fix . Have you ever changed spark plugs or plug wires ? Are there any parts stores near you ? If thier is have them check codes . It will tell you which cylinder is misfiring , and they can give you advice on what to do , sell you parts you need . Also there are videos on youtube showing how to test for what mite be causing the misfire . I wouldn't drive it too much , you don't want to mess up the catayltic converter because they are not cheap .
Window regulator is bad in the drivers door . Do you know what a regulator is ? The Trainer 24 Power Window Troubleshooting Do you know anything about automotive electrical testing ? How to read an use a wiring diagram ? Do you know there are two side to a electrical circuit ? B+ voltage an a ground side . Plus there is electronic control modules and class 2 serial data network involved . When you push the switch for a window othen then drivers window on the drivers door . a class 2 message is sent to the other doors modules . The correct module will then open it's window . http://www.bbbind.com/free_tsb.html Check out free wiring diagram here .Enter vehicle info . year , make , model and engine size. Under system click on body & accessories , subsystem click power windows . Click search button , then click each link one at a time .
What code's and were they diagnosed , You can't just pull a battery cable and have the light go off . If the light comes back on there is a hard falt . Trouble Codes Just incase your not familiar with DTC'S and OBD2 diagnostic's
Before you replace your catalytic converter, you can disconnect it and take if for a drive. If the problem goes away, you know you may have a bad component. If the problem is still present, might have other problems.
It may be the throttle position sensor (TPS). It is located where the intake air (from air filter) attaches to the intake manifold. The TPS connector should have 3 wires. The TPS controls the air/fuel mixture.