Air substantial faulty how expensive and important it is to fix it and the consequences if ignored

• Drivability issues, including one or more ignition misfires
• Diminished engine performance
• Poor fuel efficiency
• Cylinder misfire codes will likely accompany a code P1320
• And then you are stuck on the side of road when engines fails. I.s sorry there is no magic mouse milk fix for this. Yes it will be rather expensive to replace all the coils.

The Internet, though, has a large number of web sites where
you can buy service manuals and schematics from bookstores,
publishers, and other collectors. Here is just a sampling of
what sites are out there:

Chilton Repair Manuals
http://www.chilton.cengage.com/

Haynes Publishing
Haynes auto manuals
http://www.haynes.com/

Factory Automanuals
http://www.factoryautomanuals.com/

Vintage Books
Vintage books com Rare used and out of print books
http://www.vintage-books.com/

AutoLit
http://www.autolit.com/home.htm

When the check engine light comes on it is usually time to have your car serviced. If you have access to a OBD unit you can read the fault codes and reset the engine check light. If you don't have such a unit, take the car to a service center, and they will check the system. Do not ignore the check light.

Then the light is telling you either that there is a problem with the airbag system or that it needs servicing.

The fix starts by getting it to a repair garage and getting the codes read to enable a diagnosis. You can then decide what to do next. If no fault is found with the system, then the service light may just need to be reset (easy, but not a DIY job as you need specialist equipment and software).

Ignoring it is not an option though. Faulty airbag systems can and do detonate without warning; at best the car is a write off at worst you and possibly others are write-offs. Not good.

All these codes indicate you have a misfire on cylinder number 5.
P1399/P0300 - Random/Multiple Cylinder Misfire Detected
P0305 - Cylinder #5 Misfire Detected

Causes:
- Improper spark plug at cylinder #5
- Insufficient compression at cylinder #5
- Incorrect fuel pressure
- The injector circuit is open or shorted at cylinder #5
- Fuel injector #5 may be faulty
- Intake air leak at cylinder head

Solutions:
- Perform Injector Service
- Replace Spark Plug #5
- Replace Injector #5
- Replace Ignition Coil #5

It sounds like the engine management computer is not getting any signal from the Air Flow Sensor. The signal from this sensor is ignored by the computer until the engine has started. Check the wiring plug for a poor connection where it is connected to the Air Flow Sensor, The sensor is located in an alloy assembly on the large tube that runs between the Air Filter and the inlet manifold. It could also be that the engine management computer is faulty and can only be fixed by replacement of the complete unit.

CODE P1278- HEATED OXYGEN SENSOR 1 SLOW RESPONSE.POSSIBLE CAUSE EXHAUST LEAK AT EXHAUST MANIFOLD OR PIPES.FAULTY PRESSURE REGULATOR LEAKING OR FUEL INJECTORS LEAKING.AND FAULTY TPS SENSOR.

The compressor belt needs to be tightened a bit to stop the skreeching. The worse that can happen is the compressor could lock up, throw the belt and other belts and leave you stranded, other then that it could spit out metal and pollute the rest of the system causing a more expensive repair bill.

MAP and O2 sensor are two separate items. MAP, reads manifold pressure, O2 reads exhaust content. O2 sensor often is a false reading not to be ignored but should not be immediately changed till other items are corrected. MAP sensor is often mounted on the firewall and can be identified as having an electrical connector and a vacuum hose attached to it. (ask a parts house to show you one and it will make finding it easier) Check for vacuum leaks in the hose and make sure the hose is well connected at both ends before changing the sensor. You may also want to clean the Mass Air Flow sensor located between the air duct hoses running from the air filter box to the throttle body. There are two small wires inside it that can be cleaned carefully with carb cleaner and a Q tip.If dirty, it can cause idle fluctuations or stalling.

Sounds like a faulty ignition barrel! If you take off the trims underneath the steering column you'll be able to gain access to the ignition barrel casing where the key goes. By undoing the casing you'll be able to turn off the engine with a simple flat bladed screwdriver.

Ignition barrels arent too expensive to have replaced, the other problem that might occur is the chance of needing a new set of keys or to have your current keys programmed to the new barrel (Normally a new set of keys is the common procedure with a new barrel)!

Hope this helps