Spark plug Bosch or Denso

Yesss got denso coils and spark plugs off their site and they have been great

I just replaced my oem densos with some Bosch plugs that were labelled as being pregapped 1.1mm. I wanted them to be 1mm and checked with a gauge and Lo and behold they were already at 1mm. Whacked them in and improved my fuel consumption immediately.

I took it back in after setting the DPR to 2.5± 2.5 mA, checking again for any vacuum leaks, tightening down all the exhaust components, and changing out the spark plugs (again). I also checked the O2 sensor, it was fluctuating between .1v-.7v continuously.

And, before you get too far, are you replacing with the right plugs? I presume it’s the 2AZ 4-cyl since you’re not asking us how to get to the back plugs. The right ones are the Denso Iridium Long Life or the NGK Laser Iridium.

To be honest the last plug VW went with , the 101905601F (OEM clones Bosch copper nickel FR7HE02 Or NGK ZFR6T-11G (5960) Copper Nickel, Beru BRU-Z272 copper nickel ) for the 2.5 is best. It’s one shade cooler and will have less spark knock. You have more timing.

I ended up leaving them as is and the car seems to be working fine.

As long as the Bosch ones match the factory specs then I’m sure they are fine as many other parts and sensors on these cars are made by Bosch.

i bought ngk plugs and bosch platinum triple diode plugs and i got the coil pack off ebay.

the densos work fine, the point of swapping is not for any performance gain, rather to prevent shattered ceramic from raining into your cylinders

I said from the get go that the Densos were running like ****. Especially at wot around 110mp/h it felt like the engine was hesitating and lacking power. Idle was smoother with the Denso though.