I took my 97 sedan (97k miles) to Jiffy Lube for an oil change today, and they suggested I get a Coolant Flush and a Fuel Injection Cleaning. I let them do the Fuel Injection cleaning. I thought it was worth a try.. It seemed to be doing something, as tonnes of carbon came out of my exhaust.

But afterwards, as soon as I started up my car, the Check Engine Light came on. I told the Jiffy Lube guys this and they said it was "normal" - and it would go away within a couple of hours, after the lines finished cleaning themselves out.

Is there any truth to this?? I just had my 90k checkup, and the engine light hasn't been on at all until I had this cleaning done. Should I be worried?

 

You could have fried a sensor for the O2 or EGR, you likely will need to have the ECU reset. If that fails to keep the light off you will need to replace the sensor. This has happened before to other cars I know--I suggest asking Jiffy Lube to pay the bill if you need to replace a sensor.

 

maybe they forgot to plug a sensor back in?

 

Next time you want a FI cleaning try this...

Every 6 months I get a 1 pint bottle of rubbing alcohol with the HIGHEST percent isopropyl. Some will say 91% but I found that Wal-Mart has 97%. that means it's only 3% water, and since injector cleaner is 99% alcohol then why spend $2-3 on that when you can spend $0.95 on alcohol.

Add the alcohol to a half tank of gas and then fill it up. Then run the tank almost empty and fill it up again. That will help run the alcohol through the system and clean the injectors.

I have been doing this for about 3 years and have no problems.

 

I donno about the O2 and EGR sensors being fried or disconnected.. my car seems to be running fine. Even better than before really.. acceleration is ok, idling is normal (800-900 RPM). Not sure about my mileage at the moment.. as I haven't driven it too far yet.

If the lines just have to run clean for a couple hours.. I should know by Monday evening. Guess we'll see.

I'm going to go reset my ECU now though.

 

Well.. the check engine light hasn't come on since I reset the ECU, so I guess everything's alright. Maybe they just didn't disconnect the 02 and/or the EGR sensors when they did the fuel injection cleaning.

 

Actually, sounds more like the engine tried to stall while they were feeding the cleaner in. The code was probably a misfire as the engine tried to stall.

My car did the same as I was using Seafoam thru the PCV port. I actually had a code reader, and came up with some interesting info: before you shut the car off after a misfire, the code will read P1399 which is something about a bad glow plug (diesel, eh?) apparently after you turn the car back on once the code has been stored, it converts to the correct code (P whatever for whatever cylinder misfired).

Cleared it once, never back since.

-Chris