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Service engine soon light

I have a 98 Chevy Tahoe. Yesterday when I started the car it was running really rough. Usually it gets smoother as you drive and the car gets warm. I drove about 1 1/2 miles and turned off the engine. I paid some bills then got back in the car and when I started it it was still kind of rough. I was on my way to my bank and the service engine soon light started flashing. Hmmm, should I go home or go to the bank? I went to the bank, figuring I might not be able to drive the car today. When I left the bank, the car was driving pretty smooth. I'm thinking maybe I had some crap in my gas and it worked it's way out. But the light is on all the time now. I read somewhere that if you start the engine so many times and the computer does not sense the same situation again, that the light may reset itself. If there was just some stuff in my gas and making it's way out, is this possible? If it's possible, how many times would I have to start the engine, and how far would I have to go? I went back to the bank today and the car is running great. I am confused. Any help would be greatly appreciated. Thank you.

Reply to
Zanthena
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The only way to know is to have the code read. Flashing means you are in danger of harming the emissions system if you keep driving.

Reply to
Jim

You probably have a bad O2 sensor... they are not cheap either... but it is needed or you can do more damage to your emissions system. Its driveable, but I wouldn't recommend driving it very far and not getting it checked...

Good Luck

Fwed

Reply to
fweddybear

Don't go into a shop and say "I think I have a bad O2 sensor". There are quite a few things that can cause what you experienced and blindly jumping to conclusions will get you no where.. You need to get the codes read and find out what code trouble the computer sensed and go from there.

-Bruce

Reply to
Bruce Chang

I'm going to a bridal shower tomorrow and already secured a ride, but I had to go to the store to pick up a card. By the time I got there, the light went out. I went to get gas and then came home. The light is still out. I guess I will take the car to the shower tomorrow. I am probably going to buy a code scanner. I have to call a guy back on Monday. My husband can fix the car, he first has to know what to look for and that is why I will buy the scanner myself. I do not want to be in this predicament again.

Thanks everyone.

Reply to
Zanthena

Reply to
Jeremy Bomkamp

I started my car today and it was real rough. I thought, here we go again. I stopped and started the car about 4 times in a row while sitting in my driveway. The service engine soon light came on right away. I immediately drove to AutoZone. The car ran perfectly all the way there. I had the guy scan for codes and it came up with two identical codes. Code P0305 cylinder 5 misfire detected. I guess the code stayed in the computer from 10 days ago. Any thoughts on the misfire. Could I have a bad wire? Or bad plug? Both times this happened it was raining and I hadn't run the car in a couple of days. So the light is out again and the car is running fine. But I will have to take care of this when my husband stops working. He has been working now 19 days in a row 12 hours a day. He is supposed to be home Saturday and then go back to work for another 4 days at least. Any help would be great. Thanks.

Reply to
Zanthena

Zanthena wrote in rec.autos.tech

Bingo! You probably have a spark plug wire, or distributor cap if so equipped, that is breaking down. Replace the plug wires, and cap, and you should be fine.

Reply to
Dick C

Hi All....

My service Engine light came on this morning.... The vehicle is a 97 dodge Caravan Sport with a 3.3 liter engine. It has 142,000 miles on it and I have kept up on the maintenance.. oil changes every 2000 miles, change tranny fluid every 24,000 miles, complete tune up every 20-24,000 miles. I have done some diagnostics on it.... the manual says to depress the trip and reset odometer buttons with the ignition switch in the off position. Once the two buttons are depressed, then turn the key to the on position and wait until the odometer reading reads codE.... then if all is good, it will return with a 999. Well... I got all that, so I must be missing something. I mean why is the result telling me everything is in good order when my light decided to come on? Is there some other kind of diagnostics I should be doing, and if there is, then how do I go about it?

Thanks in advance for any consideration..

Fwed

Reply to
fweddybear

Reply to
Shep

Ok Shep.... thanks for the advise.... I shall call my mechanic in the morning and see him about it....thought maybe I could figure it out on my own, but I guess not this time.... I suppose the tool(s) to do a proper scan aren't cheap huh??

Fwed

Reply to
fweddybear

You can get a cheap code reader for about $50. You could also take it to an Autozone and most will read the code for free. However depending on your automotive skills it probably be best to take it to your mechanic. The OBDII codes still have to be diagnosed and it is best to have a service manual to use in the diagnosis....

Reply to
Woody

I do have a service manual for the vehicle.... I am mechanically inclined, but can honestly say that I have not done any diagnostics...never needed to really. This is the first vehicle I've owned that needed this type of work....I can replace parts easy enough.... its just knowing which ones right? I will stop by an Autozone as I have to change oil and filter in my wifes' vehicle. Once I get the codes, I will report back......

Thanks for the advise Woody!!

Fwed

Reply to
fweddybear

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