hook a timing light over one of the spark plug wires.. make sure that while cranking.. that you get

My problems started a few months ago. While driving on the expressway the van died. I was told the computer needed to be replaced. Soon after the check engine light came on. I was told the van needed to 'relearn the computer' and that the fuel mix was too rich. We were told to drive the car and the problem would correct itself. My husband drives 90 miles per day and the problem still persists. We eventually replace two oxygrn sensors but this still has not fixed the problem. Now our mechanic is saying the fuel is too lean. My inspection is due and the van is not going to pass.
The next problem that occured right after the computer being changed is that the car will not start after is has been driven. The van wants to crank over but has trouble. There is also a strong smell of gas. Only once was the mechanic able to replicate this problem but still has not been able to fix the problem. Last time I was there he said there was water in the fuel filter(?) and he was hoping that this would clear the problem. usave car rental Our mechanic has said that the two problems are unrelated. All I know is that this only started once the comp was changed. Any advice would be greatly appreciated.
harborfreight tools sells a scan tool 98614... that will do the job.. so you don't have to pay to scan the check engine lights again.. normally 129... their less expensive scan tools just dont what this one does.. i use one..
write down the codes.... before usave car rental you erase the codes.. you can look at the snap shot data.. the vans computer recorded what the van was doing when the trouble code showed up... makes it easier to diagnose..
i have also found loose relay socket terminals.. where the relays plug into the load center under the hood.. the individual terminals get just a little loose.. a carbide scribe with a long thin tip can be used around the edge of the folded contact of the connector to increase the tension on the blade of the relay..
since that motor is shared with the taurus... i would like you to look over the top of the intake.. on the passenger side rear.. there is a little box mounted to the upper intake.. about the size of a pack of cigarettes.. is it made of silver metal.. or black plastic.. that should probably have been changed... the metal versions have internal corrosion problems.. it is called an EGR pressure differential sensor... if you look about 10 inches to the right.. on the back of the intake... there is a little black solenoid valve.. 2 wires and some plastic vacuum hoses.. that is the egr solenoid.. both usually need to be changed on these motors.. cost for parts is just under 100 bucks.. takes about 10 minutes to do it on a cold motor.. easily done with a 8mm deep socket..
another place to look... for problems on these.. mark the spark plug wires.. take them off. take the coil off.. turn it over.. look for cracks on the bottom... if you see cracks... replace the coil.. the cracks will leak high voltage from the windings...
Catalyst Efficiency Monitor test only switches during steady state cruise conditions of a drive cycle are counted. Switches at idle or other drive modes are not counted. The counting of front and rear HO2S switches continues until a drive cycle is completed. At that time, the ratio of total rear switches to total front HO2S switches is calculated. If the switch ratio is greater than the emission threshold, the catalyst has failed and a Diagnostic Trouble Code (DTC) is stored.The DTCs associated with this test are DTC P0420 and DTC P0430. A bad catalytic converter
If the downstream O2 sensor is bad heater circuit networking, loose or corroded usave car rental wiring connector, contaminated sensor element, the OBD II system should detect the fault setting a false P0420 code. With a strong smell of raw fuel, the oxygen sensor will be considered contaminated,
I would check the fuel pressure regulator for leakage at the vacuum hose going to the throttle body from the regulator, usave car rental could be allowing the raw fuel that is left in the fuel rail to be drawn into the throttle body with the engine usave car rental off, flooding the intake with fuel.
Now our mechanic believes usave car rental the two issues are related and the only fix is to replace the catalytic cnverters. From what I read this is not a guaranteed fix. Again, this all started when we replaced the computer. Could this be the problem? Where should I go from here?
hook a timing usave car rental light over one of the spark plug wires.. make sure that while cranking.. that you get flashes as soon as you start cranking.. like i said.. i have had the electrical half of the ignition switches fail....