pito

Well here's the deal. I was driving along normal and smooth as usual. All of a sudden the car started to have a shake to it, easy to feel since I never felt the car before. Well then I press the gas pedal and have no power. It slugs along as if in safe mode. I start to see smoke coming from under the hood so now I am nervous. So I get it to my mechanic and here is the diagnosis. Before this happended we noticed a leaking crankshaft seal and camshaft seals. He says that the oil finally got down into the camshaft sensors and killed them so to speak. When he hooked up the scanner to the car, both camshaft sensors came up no signal. Well after replacing the camshaft sensors and seals doing a timing belt and water pump job and valve cover seals the car started find and is still running poorly.

So, now he checks the EGR system. When he unplugs both plugs at the front and back the idle does not change at all??? So he unplugs vacuum lines and finds that there is no vacuum in certain hoses. Basically there is vacuum at the beginning of the EGR system coming out of the intake manifold but there is no suction after that. Is this because the car is in limp mode?? Well my mechanic checked the oxygen sensors and says that he is getting poor to no reading on the 4 of them. When he removed the 2 precat sensors they look dark like they were burnt and appeared to be original equipment. So I ordered two new direct fit ones but unfortunately they sent 3 wire plugs instead of 4 wires. After spending so much money on the previous items I have to wait till this evening to be able to order the other two Oxygen sensors.

What I am looking for is advice from anyone that may have experienced this. I am also just looking for information to verify that we are on the right track. I trust my mechanic as he has worked on many cars for me in the past including a Q45 and 929 which are pain in the *** vehciles in their own right.

My LS didnt really give me any problems other than the regular things that happen when a car is not really maintained well. Keep in mind I have had it for a few months and it now has 187000 miles but runs really well previous to this. Any assistance will be appreciated.

crazimofo

since you changed all the above things you listed..
try changing all your O2 sensors or check there ohms reading before you change them..i think that might be your problem..

let me know how you do..
try also test your MAF sensor for some readings...

pito

Yeah I think the MAF is fine but according to my mechanic he got bad readings on the O2 sensors. I am changing out all 4 by the end of the week.

pito

Well my mechanic changed the front two oxygen sensors and that didnt help. So he checked the maf sensor and unplugged it. Now usually on most cars the unplugging would shut the car off but not in this case. So he checked the contacts on the plug itself and after some diagnostic work basically the computer looks like it needs to be replaced. So I am off to find a computer tomorrow wish me luck and post anything that may help. Even if the help assists someone in the future who searches for these symptoms.

justfixit

Oxygen sensors are not your problem. Any O2 sensor problems would give you a check engine light with codes 21, 25, 26 or 28. If you have bad readings on sensors with no codes then you have a fuel or ignition problem and sensors are reading accurate but bad information.
I am guessing you have an ignition coil going bad. You have 2 ignition coils and both control 2 cylinders per head. When a coil goes bad you basically have a smooth but sluggish 4 cylinder. Most of the time the coil on the driver side above A/C compressor is the culprit as it gets more heat and less circulating air to cool.
Good luck.

pito

So how do you feel about the computer being a problem? Seeing as the diagnostics show current on a contact with the computer hooked up and no current with the computer disconnected. The diagnostic also showed no shorts in the plug that goes to the maf.

pito

Also my concern is the heavy smell of gas indicating that fuel is not being burned hence why my guy is leaning towards the computer not giving the correct signal to the maf plug. Also let me point out that when codes were first pull an IAT signal failure was noted and that signal wire is on the maf plug as is the wire that is affected by the alleged malfunctioning computer. I will have more info tomorrow as I will be getting a computer since I am already into this thing as far as money on this round of repairs.

crazimofo

yup i agree also with check both your coils...
that would cause that problem too...

pito check your email..

pito

Thank you fellas I appreciate the input. Please everyone continue with the ideas so that others in the future have a reference point.

justfixit

I feel it would be a mistake. Every time I have seen an ECM go bad (which has only been 4-5 times in 17 years) there is no communication to ECM.
Could be ECM but I am betting no.

justfixit

Code 24 or 31 for Intake Air Temp is usually set when someone leaves the MAF unplugged and tries to start engine.
Heavy smell of unburned fuel is normal when one coil is not firing 4 spark plugs. Also continual driving of vehicle with bad coil will nuke the catalytic converter.
Simple test is check firing of plugs. Then order iginition coil #90919-02197.

pito

OK thanks

I know that the plug was not undone so I am little confused. I will more than likely try the computer since I found one not too expensive and replace both coils just for peace of mind. They are easier to get.

pito

I think I will be buying the coils tomorrow. Might as well change them both.

crazimofo

Change the ECU first then run your car to see how it performs...if still the same problem try both ignition coils...

when you unplug your MAF sensor does your check engine light come on?
if not, then either your MAF is the culprit or your ECU...check voltage on it..

let us know pito..

pito

This sucks.

Ok replaced ECM, nothing different. Check engine light on. Diagnostic scanner cannot communicate with ECM. Mechanic says that there is no ignition current going to the plug.

I am highly frustrated. Would the ignition coil go out just like that with no warning signs. My mechanic says that the car is dumping gas and if the coil was bad it would cause a missfire. But not the gas dumping.

Please guys. There are a ton of guys on here with info but only 2 have shown their talents, which I appreciate by the way.