Information on how to use a Code Reader Generic OBD-II codes and the readout

Hey Eric,

Here is a great guide and video on how to use a code reader on a similar model car, the process is the same for your car.

https://youtu.be/b2IJGfImVvw

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let us know if you need anything else to get the problem fixed.

Five days ago I had a Service Engine Soon indicator checked out. The EGR valve was checked (I think it was error code 40), and turns out the EGR is ok, they told me there was a lot of gunk in fuel intake and throttle body was cleaned out. Now, from cold start, the car will cut off shortly after putting into reverse, and idles incorrectly when stopped. Everything seems fine as the engine idles down, but the engine "surges" in an odd manner (makes a wuh-wuh-wuh-wuh sound and things kinda bump back and forth) as it idles at min rpms. If I push the accelerator a little bit/increase RPMs while stopped (with foot on the brake, of course), it stops the surging action. After warming up driving for 10-15 mins, it runs fine/idles normally when stopped. Any ideas?

If you haven't driven it much in those five days, the computer may still be "relearning" its settings and operating in "open loop" in the meantime. If it persists, you might have the mechanic who cleaned the intake check it again, making sure the idle air control valve (which he might have cleaned while he was at it) is working properly.

Check for vacuum leak probably the hose on the intake or the air meter?

It has been driven quite a bit. I drove 380 miles on the first day after it was fixed (Thursday, Apr 8th) , and then it was taken on another 250 mile round-trip over the weekend. I'll keep an eye on it, it sounds like patience will be the best solution??

A number of short trips might work better for restoring the settings, but I'd say if it doesn't straighten up very soon, I'd have the IAC and anything else they might have disturbed, such as vacuum hoses, checked.

I looked it up on acronym finder, but I want to make sure what IAC means...is it the idle air control valve?

Hi old_lady_car, Yes the IAC is the idle control valve.

The check engine light appeared after shifting the car out of park and into Drive or Reverse. My fiance described the problem as giving it gas but not going anywhere. It sound to me as if the transmission maybe slipping. She drove it home from work with know problem, but after i went out to check it out, I noticed the light as the car went into drive or reverse as stated.
The car is well maintained and not abused, the idle is fine the motor is not missing. The car only has 80,000 original miles. The car has been parked since as to not cause any further damage.

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis,finding out what's going on.

But the light came on immediately today and seemed to idle a little rough.

diagnostic code shows PO440

Hello
Thanks for the donation.

P0440 Evaporative Emission Control System Malfunction

This code normally appears if the driver forgets to put the gas cap back on, or the gas cap seal is bad. double check the vacuum line from the throttle body to the purge solenoid for leaks. The best way is with a smoke machine. There could also be an issue with the purge solenoid or the electrical connection to it.



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P0440 EVAP System No Flow During Purge Possible Causes Setting Conditions

Charcoal canister is loaded with fuel or moisture
Fuel filler cap is loose, cross-threaded, damaged or wrong part
Fuel tank, fuel filler neck or fuel sending unit 'O' ring is leaking
Fuel tank pressure sensor is damaged, disconnected or it failed
Fuel tank vapor line(s) is clogged, damaged or disconnected
Purge valve vapor line is clogged, damaged, or disconnected
Purge or vent solenoid power circuit is open (check the fuse)
PCM has failed

Engine Mechanical problem
1997 Buick Century 6 cyl Front Wheel Drive Automatic

how do i reset the "service engine soon" light

The "Check Engine Light" has to be "reset" using a scan-tool. Most modern shops have them. Autozone and Advnace auto also have scan-tool (not sure if they can reset you light---call to see). They usually check codes for free. Before the light is reset have them to read the computer codes. Write them down and keep them with the vehicle. Those codes will be erased when the light is reset. If the light comes back on later, have them to read the computer codes again. Check the new codes against the ones you wrote down earlier. The codes that returned need to be checked out by a certified technician.

Can a faultering fuel pump be cause for my service engine soon light to stay on?

if the code is a lean mixture code yes, otherwise no.

a manual test of pressure will test the pump.

Roy