Most people said you must remove the intake manifold... to get into them... for more room.... I also hear every one said. it little bit hard to remove the connector ...

But it all could be done >>.. I need to do mine soon...

I need to up grade and replace both knock sensor... front and back....

buy a Haynes book it show how to do it...

some said you can replace the front knock sensor without remove the intake manifold... but you must remove the fan....

good luck please give me feed back when you replace your and how hard or easy

Thanks

Shahnawaz