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1998 Subaru Legacy outback spark plug change


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Hello i am trying to change my spark plugs in this vehicle. The issues that I am having with the vehicle is that when I go to drive it in the morning even in warm weather the speedometer doesn’t move until I hit the 2nd or 3rd gear and it’s sort of sluggish starting off. Then when I’m on the interstate my vehicle starts to jerk at 60+ mph and when I have the ac on it jerks at 40 mph. I am hoping it’s just the spark plugs and if it is would someone have a comprehensive guide on changing them?

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nothing wrong with catching up on any regular maintenance, but I'm not convinced plugs will cure the problem(s) you are experiencing.

 

Is the CEL on? have you scanned the car for codes? post them up and soeone may be able to help you.

 

What does the trans fluid look like? remember to check it while idling - it's the only fluid checked that way.

 

You could start a new thread asking for a shop recommendation near Omaha, someone may be familiar with a Subaru-friendly mechanic.

Edited by 1 Lucky Texan
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1 hour ago, 1 Lucky Texan said:

nothing wrong with catching up on any regular maintenance, but I'm not convinced plugs will cure the problem(s) you are experiencing.

 

Is the CEL on? have you scanned the car for codes? post them up and soeone may be able to help you.

 

What does the trans fluid look like? remember to check it while idling - it's the only fluid checked that way.

 

You could start a new thread asking for a shop recommendation near Omaha, someone may be familiar with a Subaru-friendly mechanic.

I just used an Engine diagnostic tool on it and it pretty much showed that it is either the engine coil and or spark plugs that need to be changed. It said that the cylinder four is miss firing and the catalyst efficiency is below normal

Edited by Chrisg12222
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many things will trigger a P0420 - even though cat. conv. is part of the definition, you are wise not to assume the problem is the cat. , sometimes it is just a misfire, vacuum leak, or exhaust leak - other stuff.

 

NGK spark plugs are MUCH preferred. Check your manual. OEM also preferred for plug wires - your car could easily need both. If you still experience cyl4 misfires after a plug swap, swap a different plug wire with cyl 4 and see if the misfire follows the wire - or just get a new set. Sometimes spraying a little water from a plant mister around the plugs, wires, and coil at night will show bad parts arcing - might even cause the engine to stumble.

 

In future, post the actual codes you read.

 

search here, subaruoutback.org and even Youtube for some DIY help.

Edited by 1 Lucky Texan
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To change plugs:

A search found this: http://www.subaruoutback.org/forums/111-gen-1-1995-1999/390178-how-i-changed-my-spark-plugs-ej25d-tips-future-readers.html

 

It's a PITA on the EJ25D engine in you OB......done it, didn't like it. Your engine is in the '96-'99 OB/GT/LSi, '98 Forester and '98 Impreza RS

Buy the NGK platinum plugs which are good for 60K or if you're cheap get the copper version and do 'em again in 30K miles.

RE: the misfire? see Lucky's info above, but I'd also guess the valves have never been adjusted as that's also a PITA, or worst case scenario you have a burnt valve...been there, fixed that w/a 2.2 (EJ22e) swap.

Edited by wtdash
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  • 3 years later...

Howdy and good greetings. My 1998 Subee has been doing me proud and I feel will go a bit longer...indeed mileage is high (203868) and I've been teaching myself the simple TLC tune up check list, I am now going to try and figure out replacing my spark plugs. New ones are Bosch double iridium,not sure if those will help or harm my pony. Anywho I was hoping a kind soul could lend some knowledge in regards to these codes...much obliged 

Screenshot_20210817-132656.png

Edited by Jubilation5463
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Record them, clear them and see what returns.  That's a long list.  How long has the CEL been on?

Plugs you need to put the socket in the hole, connect a 3" extension and the ratchet.  Some spots you can get a universial joint and a 3 & 6 inch extension on to get the plug out and back in.  

Not a good design for sure.  NGK plugs for sure.  I go copper core and NGK wires as well.

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  • 3 weeks later...

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