coolant leak/check engine light

hi
i have a 98 lesabre. it had a coolant leak. the mechanic replaced the plenum and the upper and lower intake manifold gaskets. this stopped the collant leak, but i have a check engine lite warning now which we can't figure out.
i,ve never had a check engine alarm before. i,m worried about driving this car under this condition. i changed oil 3 times. i changed coolant. the levels check ok. the car runs good.
thanks in advance for any help.
pothound

Welcome to AF. How can you worry about the CEL when without knowing the code there is no way to determine what the cause is? Have the code read and post back for help.

Check Engine Alarm??

Are you sure you don't mean " Check Gages " ?

http://img.photobucket.com/albums/v294/Jr3800/BillShirt007.jpg


Something like in the above Pic?

Welcome to AF. How can you worry about the CEL when without knowing the code there is no way to determine what the cause is? Have the code read and post back for help.
the code # is po442.
thank you
pothound

Hello, most common is gas cap see if its there
A code P0442 most likely means one or more of the following has happened:
A loose or improperly affixed gas cap
A non-conforming gas cap (i.e. not factory/original brand)
A small leak/hole in a fuel vapor hose/tube
Other small leak in EVAP system
Faulty vent o-ring sealPossible Solutions

With a P0442, the most common repair is to:
Remove and reinstall the gas cap, clear the codes, and drive (http://www.obd-codes.com/p0442#) for a day and see if the codes come back.
Otherwise, replace the gas cap, or
Inspect the EVAP system for cuts/holes in tubes/hoses

the mechanic thought he had it fixed. the check engine light didn't come on for 3 days and now it is back. this must be a nightmare for a garage. could the new gaskets be faulty? have the torque settings changed? if my mechanic does not find the problem this week, we will be taking a trip with the check engine light on. how much damage will this do?
thank you pothound

If the code is 442 this is a slight vacumm leakor fuel vapor pressure leak in the evap emissions system, usually not a safety or driveability issue, assuming there is no fuel leak in/ around the tank.

i dont think the gaskets are your problem.i'd be looking for a loose or cracked vacuum line/hose that tech the may have disturbed while doin the intake Good Luck

my mechanic found 2 hoses loose which he secured. now the po442 is gone. it is replaced by a po420 code. i took the car to buick. the results of the test are replacing the vapor canister purge solenoid, the cat, and the down stream oxygen sensor. i couldn't afford to let buick do the job. what would be a good cat replacement?
thankyou
pothound

i understand about the $$$ have you can you check yourself??do you have access to a scanner??not to say they (parts) are'nt all bad but...here some info on P0420
P0420 OBD-II Trouble Code

Technical Description

Catalyst System Efficiency (http://www.obd-codes.com/p0420#) Below Threshold (Bank 1)
What does that mean?

The catalytic converter has an oxygen sensor (http://www.obd-codes.com/p0420#) in front and behind it. When the vehicle (http://www.obd-codes.com/p0420#) is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor (http://www.obd-codes.com/p0420#) reading should be fairly steady. Typically the P0420 code triggers the Check Engine (http://www.obd-codes.com/p0420#) Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

thank you
now i need to find after market o2 sensor cat and purge soleniod that will work, prefer a direct fit cat. would it be hard for a novice like myself to install these parts? the o2 sensor is downstream.
pothound

hi
after 1200$, it is working without the check engine lite. a generous amount of antifreeze went thru the engine. my mechanic suggest i trade it off. i didn't change the downstream o2 sensor. i'm afraid to drive too far. any comments would be appreciated.
thank you
pothound