P0133 P0134 and P0301 in 1997 Chrysler Sebring

A friend of mine has a 97 Sebring, in which the check engine light is on, and stays on. I used my Atron II to pull up codes, and came up with the 3 listed in the subject. One thing to note is that her father recently replaced the O2 sensors. The codes seem hard in the fact that the check engine light stays lit after turning the car off and on again.

I did suggest undoing the battery negative and letting it sit for 10 minutes before replacing to reset the computer. Of course, it could be a number of things that can cause a sensor to send a DTC, but does anyone have any first impressions of what they would look for initially?

check for a blown fuse in the fuse box that says 02 sensor, If there isn't one check the circuit to the upstream 02 sensor, either the signal isn't getting back to the pcm, or the heater circuit isn't functioning or the misfire is bad enough that the 02 is staying rich or lean for too long and the 02 sensor isn't likely bad it's just telling you the condition. What engine is in it?

good luck and keep me posted

Jeff

Jeff, thanks for the reply. The engine is the V6 2.5L model. I talked to her at work today, and she called her father about the spark plugs/wires. The spark plugs and wires have not been changed for the life of the vehicle (has about 97,000 miles). This could be the most logical place to check, and it's my intention to pull the plugs and check their condition. I also obtained a copy of the Chilton manual from the local library, and it shows that the wires should have a resistance 3000-6700 ohms/foot. I also plan on checking this as well on my VOM meter.

Also, she mentioned that a shop told her that the back 3 spark plug and wires are a bear to get to, and would involve removing the intake manifold to even allow access back there. What's your experience with these? The shop may be right, but there may be other "ways" to get to them without engine disassembly. On my old 1992 Grand Am, there was a method of rotating the engine fwd on the mounts (pushing from the back and chocking the wheels) to allow easier access. Minivans can be worse!

On my 1990 Mustang (using the EEC-IV system on a 5.0), one can heat up the O2 sensor (using a torch) then measure the output voltage for a "basic" performance check. Can the similar process be done on the Chrysler? Like the Mustang, I assume that an improper O2 sensor can lead to excessive times to reach a closed loop condition.

Jeff, as always, thanks for your input, and I'll keep you posted as things develop.

Buy the proper plugs and wires from the dealer, I don't recommend replacing the distributor cap and rotor because if you're not careful you can damage the ignitier in the distributor and the distributor will have to be replaced. They are really expensive, Plus the cap and rotor hardly ever fail. If the wires and plugs have never been replaced then they are on borrowed time as is. The intake plenum does require removal, they're is no way to cheat the wires out because the plenum goes right over top. Not a job you want to do more then once but it's not as difficult as you might think. While you're there check for any wiring problems to the 02 sensors. I'll check for any tsbs regarding the 02 codes. Those cars are paticular about the brand of plugs that are used and the injectors can get gummed up rather frequntly, putting some sea foam in the tank or having a motorvac service prior to the tune-up isn't a bad idea. I don't recommend a motorvac with new plugs installe dthough. The carbon and cleaner can foul new plugs.

good luck and keep me postted

Jeff

Jeff, again thanks.

I assume that if I follow the instructions in the Chilton or the Haynes manual, it shouldn't been too diffucult. Correct? My sister owned a Chrysler Conquest, which was a neat little car, and I did the repair work for it. The first job was repairing the oil pump/timing chain assembly, which was really time consuming. You end up disassembling part of the engine. Ran great after that. I do remember looking at the setup (with the asjustable chain guides and all) and thinking this was kinda strange. Ended up replacing the turbo bearings later. This is really the only Chrysler vehicle I've worked on extensively. It also was time consuming because I was helping my father in law replace the engine in his Chevy 1500.

I almost guarantee she'll take the advice and buy Chrysler original parts. I have advised her of that. The 90s Ford Escorts were also very picky when it came to plugs and wires, and you couldn't go wrong getting Motorcraft originals.

Craig

Yeah the chilton's manual should walk you through it pretty east , you'll need a plenum gasket and maybe an egr tube gasket as well! Might as well change the pcv vale while you 're in there too

Good luck and keep me postted

Jeff