I have copper plugs in my 04.5 T5 with full evolve exhaust right now. I have been throwing a P0420 code ever since the first tank of non california gas (plus it is a lot colder here in the Northwest). My ques is, do i need platinum plugs? Will it stop throwing P0420 code?
It is a high flow converter, can it really be bad after 3 yrs?
Evolve will not return any of my calls or emails about this or a coilover issue im having!!??

 

Copper / Platinum, fried ecu, Superchip, high flow converter, weather, codes...

You are making my head hurt. You have a lot of stuff going on hear.

Copper vs platinum - Copper is a better conductor than platinum and may perform better. However, platinum lasts a lot longer and is why many mfgs like to sue them. Iridium has the advantage of better performance than platinum but with similar longevity. The down side is that they tend to be expensive. The copper plugs should last about 20K miles. If you are eating plugs then you may have the wrong plug / temperature range.

For the record, the Volvo plugs tend to be an excellent choice. NGK and Denso are also very good. I have not have very good results with Bosch however.

The fried ecu - did the car happen to have the older version of the K&N intake? There were issues with the ecu over heating.

Superchip - I am not aware that Superchip even makes an upgrade for the S40/V50/C30/C70. There are much better choices on the market: IPD Softloader, BSR, RICA.
Stan

 

Just to add to all the useful info here.All plugs are "copper" ones.When you say copper no one means that the actual electrode is made of this material as it would melt inside the chamber at that temperature.What it means "copper" is the electrode inside the plug but all current plug you can buy does have this.Then it comes to regular(BS) ones for lawnmowers better platinum's for longevity and then Iridiums for performance but less millage..Spark 101 is less the surface area of the center electrode is more powerful the spark will be but please do not adjust the gap to like when you were using regular(BS) plugs as it will not be better but worse.Tuned cars should get a one colder plug so lets not forget about this when it comes to upgrade.

 

I'm guessing you bought John's old car????

Okay, now the Bosch Copper plugs are IMHO the better plug over Platinum any day of the week. Like AutoNaut said, Copper plugs wont last as long but there cheap as all get up. So stick with copper plugs and replace them more often.
Cali has 93 Octane gas and the issue might be coming from the top gas here in the PNW being 91 Octane. But that's just speculation on my part. With the code your throwing is something that a lot of people have seen with aftermarket Cats. If in fact the cat is good, You can probably get rid of the code with a O2 sensor spacer. Worked for many people.

Now the car does not have any tune on it right? You may want to look into getting a Stage II tune to utilize the 3" Downpipe in your car, preferably from iPd. Superchips is a horrible company for many reasons, I would not recommend anyone to do their tuning through them. On the Topic of Evolve/Elevate, they're...... Search my friend, most reviews are not to the liking of them.


With the coilover issue your having, and the springs being cut, I really think your gonna be S.O.L. there. I'm sorry and I know it sucks. IIRC your wanting to raise the car, correct? I would take the coilovers off the car and install H&R sport springs. They'll still give you an aggressive drop but it they aren't harsh at all.

My old S40 with H&R's


If in you did buy John's old S40 then there is a lot of history regarding your car over on Swedespeed.com
Lot's of guys over there including myself, would love to see your car back over there too.

Where abouts in the Northwest are you? We just had a mini S40 GTG on the 3rd of this month and we're gonna be planning something big for the spring.

 

Haha, you'll get no argument from me that Evolve is a $hit company. I had a bunch of there stuff on my S40 and none of it worked right. There tune also screwed up my ECM and had to fix it. They tried blaming it on the K&N but it in fact was there fault since conflicting software was found on the ECM.

I would still suggest going to springs and selling the coilovers to pay for them. You'll still get a slight vibration that you'll be able to deal with it's not nearly as bad as what you getting now.

My S60R's sitting in the garage too because of all the damn rain. The weathers been crap up here for the last little while. I can't wait for spring in the NW!!!