I've got a 98 Legacy 2.2 with 115k that I'm just starting to learn how to do even the basics for a tune. Basically until last week changing the oil and and wiper fluid was the extent of my shop experience.

 

Anyway, it seemed like my mileage had been suffering recently (down to 26-27 from close to 30) so I thought as something easy to try and they were due anyway, I would tackle spark plugs. Followed Haynes, got NGKs and thought I got it done but I definitely messed something up and now I think it's missing sometimes and at high speed is louder than normal (or maybe i'm just paranoid). So I guess I'm looking for any thoughts on what I screwed up on changing the plugs--something a beginner would mess up particularly if no one told you.

 

Also, assuming that the plugs weren't the problem orginally, what else would be the next easy, cheap solution to try to improve gas mileage. Fuel filter? One friend suggested using some fuel injection cleaner too before doing any actual work?

 

Thanks.

marshall

Did you remove/open the air filter box or any other of the related components to access the plugs? You may have just not connected them properly. This happened to me and made the car sound "throatier".

Also, if there has been a drastic change in performance after doing the work, you may have disconnected a vacuum line.

I've got a 98 Legacy 2.2 with 115k that I'm just starting to learn how to do even the basics for a tune. Basically until last week changing the oil and and wiper fluid was the extent of my shop experience.

 

Anyway, it seemed like my mileage had been suffering recently (down to 26-27 from close to 30) so I thought as something easy to try and they were due anyway, I would tackle spark plugs. Followed Haynes, got NGKs and thought I got it done but I definitely messed something up and now I think it's missing sometimes and at high speed is louder than normal (or maybe i'm just paranoid). So I guess I'm looking for any thoughts on what I screwed up on changing the plugs--something a beginner would mess up particularly if no one told you.

 

Also, assuming that the plugs weren't the problem orginally, what else would be the next easy, cheap solution to try to improve gas mileage. Fuel filter? One friend suggested using some fuel injection cleaner too before doing any actual work?

 

Thanks.

marshall

 

o2 sensors, and fuel filter.

new oem plug wires, and a fuel filter is super eqasy to do. Its right on the driver strut tower.

Hi xcracermg, welcome and congratulations on your Subaru!

 

If front o2 sensor was never done it may be past it's useful life. How about a nice fuel system cleaner like redline si-1 (can get at pepboys i think and maybe autozone)?

 

When it's somewhat dark outside, you could idle the engine and look for any sparks around the plug wires and coil pack maybe? Especially after misting some water over it all with a spray bottle.

Hang in there, it can't be too bad.

 

Check the stuff you took out to get to the plugs.

1. MAF sensor plug on the air cleaner assembly - check ALL connectors are plugged in.

2. Any hoses disconnected - vacuum to the valve cover or the intake

3. Plug order? I have to ask .

Well, just found one mistake made. Plugs I bought were the BKR6ES instead of BKR6E that are stock I thnk so I got the cheapo ones. Guess I'll try that first. Too bad its snowing now.

I've got a 98 Legacy 2.2 with 115k that I'm just starting to learn how to do even the basics for a tune. Basically until last week changing the oil and and wiper fluid was the extent of my shop experience.

 

Anyway, it seemed like my mileage had been suffering recently (down to 26-27 from close to 30) so I thought as something easy to try and they were due anyway, I would tackle spark plugs. Followed Haynes, got NGKs and thought I got it done but I definitely messed something up and now I think it's missing sometimes and at high speed is louder than normal (or maybe i'm just paranoid). So I guess I'm looking for any thoughts on what I screwed up on changing the plugs--something a beginner would mess up particularly if no one told you.

 

Also, assuming that the plugs weren't the problem orginally, what else would be the next easy, cheap solution to try to improve gas mileage. Fuel filter? One friend suggested using some fuel injection cleaner too before doing any actual work?

 

Thanks.

marshall

 

 

replace your plug wires if they're old and add a new air filter!

BKR6E-11 ?

 

 

Check that all the wires are popped back onto the new plugs. A loose connection is likely.