Code P0302 cyl #2 misfire & Code P0300 Multiple cyl misf

S70 Guy · Post by **S70 Guy** » 28 Nov 2005, 11:15

Just purchased 98 S70 GLT 145K on it. Had check engine lite on. After replacing a few items the CE would come and go. It was off so I was feeling lucky and went to the E-Check.

Put in before E-Check;
New Battery
Bosh plugs, Wires, Distrib cap and rotor
Replaced air and cabin filter
Bosh fuel filter
Ran a few tanks of 93 octane gas and fuel injector cleaner (pop & pour)

Drove it on highway for 20min
Took it for emisions test and failed.
Gas cap pressure good
Code P0302 cylinder #2 misfire detected
Code P0300 random/multiple cylinder misfire detected

What else could cause misfires like that? Ignition coil ?
Is there a code list somewhere on here?

Thanks in advance.

White850Turbo · Post by **White850Turbo** » 29 Nov 2005, 07:35

It's the crappy Bosch plug wires; they all do that. Replace them with OEM Bougicord and you should be fine.

bigmuse · Post by **bigmuse** » 17 Aug 2006, 13:57

I am having a similar problem. I'm getting an ODBII P0302 code on my car(listed in my sig). I replaced plugs, wires, cords, dist. cap and rotor all about a month ago. Just yesterday my check engine light came on with the P0302. The replacement parts I used are all listed in my sig as well. The plugs were supposedly pre-gapped to the correct specification. Should I try replacing the brand new plug wires as a previous poster mentioned or try something else. How do I tell if the spark plugs are funtioning properly? Shouldn't the bottom of them be gray-ish colored after a couple months use? Will a misfiring cylinder hurt anything? I haven't noticed any difference in performance or anything else. It is idling very smoothly and doesn't appear to be knocking. Please help!!! Thanks.

the underlord · Post by **the underlord** » 17 Aug 2006, 15:14

don't use platinum plugs..

just go get OEM plugs... that'll fix your problem.

bigmuse · Post by **bigmuse** » 17 Aug 2006, 16:12

thanks, anything else i should check for when i pull the plugs out? are the platinum +4's just bad plugs or my engine doesn't like em?

Post by **pfeener** » 17 Aug 2006, 16:12

+1 on everything that's been said. Stick with the genuine Volvo plugs and wires. Get the parts from FCPgroton. They have the Volvo plugs and the Bougicord wires are exactly what you would get if you walked into the dealer and pluncked down the big bucks. (and I mean exactly, right down to the stenciling and the Volvo brand name)

bigmuse · Post by **bigmuse** » 17 Aug 2006, 16:24

is there a plug i can get locally at autozone that will be similar to the stock volvo plugs? i'm not having any kind of black exhaust or anything and my car seems to be running better than ever so i dunno. it's an N/A car also, which i have read that the turbos have problems with the platinum plugs. thanks again for the advice guys.

bigmuse · Post by **bigmuse** » 17 Aug 2006, 16:27

how would i test the wires to see if they are operating to specification? voltmeter?

bigmuse · Post by **bigmuse** » 17 Aug 2006, 19:25

i picked up some ngk v-power. puh-puh-puh-puhlease help me with the other stuff.

Post by **MadeInJapan** » 17 Aug 2006, 21:51

People here have told you what to get and you go and get something else. What do you expect? The Volvo engines are finicky and don't like certain kinds of plugs. If you can't get the Volvo plugs for some reason, then you can use Bosch Copper plugs FR7DC. In fact, with an N/A engine, that's what I would recommend anyway. Bougicord wires (www.fcpgroton.com is your friend) too.