About a month ago i noticed my Disco start to sputter at low speeds but it wasn't anything major and my gas mileage and power stayed the same. Fast forward to today and my service engine light comes on and i take it by auto zone and they read it as a cylinder 4 misfire. The Disco still runs the same and i still have plenty of power, i cant tell anything different. I pulled the plug and it looks to be firing normal. No coolant loss, no coolant apparent in the oil, and everything else seems to be fine. I'm going to take it to my mechanic Monday morning for a more in depth diagnostic but wanted to check if anyone had an issue like this or what they think it could be? I got 92K miles plugs and wires have been replaced and 90K service done. Wires are from the dealer and blue and plugs are bosch platinum 4's.

 

I have my theory but I cant post it, sorry.
Good luck.

 

If you have not already, check if your oil is really low.

 

Oil is fine and clean. Funny thing is my service engine light went off on its own the other day. Odd. Mind you the day it came on it was about 110 degrees here. Not sure if that played a role but everything seems to be normal now.

 

thas the only code you got?

 

according to the guy at Auto Zone yes that was the only code and like i said the light has since turned off. However, today it started to struggle going uphill like it wasnt getting enough gas but there still is no light. O2 sensors starting to go? MAF?

 

ok...this could be a real long list on items you may wanna check

Did you ever take it to your mechanic?

 

Throw away those Bosch platinum 4 plugs and use the OEM Champion plugs. I replaced the original Champion plugs at 60k miles and have 15k on the new ones with out any lights, codes, misfires, etc. I know that a lot of people on this forum are going to come out of the woodwork and defend the Bosch plugs but this is my experience and i am sticking to it.

 

Need to quit guessing, MAF or 02's, neither are related. Go drive the truck hard, try to get it to throw some codes again and this time get the fault code numbers.

Buick, why replace the oldest, largest manufacture of plugs with another. Most people with their complaints regarding Bosch are just passing along old wives tales, none of which is first hand. Tell me why would companies like Mercedes and BWM use these if they were a bad plug..
I changed my Plus 4's out at about 88,000 mile while doing a head gasket, never had any problems with them.

 

and mercedes also recommends changing spark plug on their products anywhere from 30k all the way to 100k miles. all depending on the engine.

I have seen +4 throw lights so you never know.