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Ready to race!
- Location
- Whitby, ON
- Car(s)
- 2018 Golf TSI 1.8
I upgraded to a KN drop-in filter and an inlet elbow before my stage 1+ tune and my following misfires. I don't think you will solve your misfires & EPC just by changing your inlet elbow, but it could still be a fair upgrade considering you already have an IS20 and an upgraded intercooler, and even if you downgrade to IS12.
With just a drop-in filter (KN, Afe, AEM, etc) to your OEM box and an elbow, you will have more than enough flow for your IS20 tune (and even if IS38). No need for a complete intake!
As I mentioned, I was having the same misfires and EPC light happening at the same time as you described (it doesn't mean it could be the same cause).
Even though Uni says OEM plugs and gap, I adjusted my OEM plugs following APR's recommendation for their tune: "APR recommends properly gapping the factory spark plugs to a tighter gap (Ex: 0.024" ±0.002" or 0.6mm ±0.05mm), properly installed and torqued (Ex: Per the manufacturer's specifications), and maintained with a shorter changer interval (Ex: 10,000-15,000 mi or 16,000-24,000 km)."
And use a proper tool when gapping, do not tap the plug on a flat surface to lower the gap. I gapped mine after watching this video from APR posted in 2015:
Together with the plugs, I changed the coils to APR's, which promises a bit more energy than OEM, with only a few more bucks. At the same time, I had my fuel system + intake cleaned.
After I followed the above, zero misfires or EPC light, all excellent. I'm not saying this will solve your problem, just sharing how this solved mine.
Regarding your PCV, when it is bad to a point to cause misfires, it is usually also making noises, rough idle, leaking oil and showing other codes. And your car is still "young" for a PCV issue. I don't think it is your PCV causing misfires.
Did you change your coils?
With just a drop-in filter (KN, Afe, AEM, etc) to your OEM box and an elbow, you will have more than enough flow for your IS20 tune (and even if IS38). No need for a complete intake!
As I mentioned, I was having the same misfires and EPC light happening at the same time as you described (it doesn't mean it could be the same cause).
Even though Uni says OEM plugs and gap, I adjusted my OEM plugs following APR's recommendation for their tune: "APR recommends properly gapping the factory spark plugs to a tighter gap (Ex: 0.024" ±0.002" or 0.6mm ±0.05mm), properly installed and torqued (Ex: Per the manufacturer's specifications), and maintained with a shorter changer interval (Ex: 10,000-15,000 mi or 16,000-24,000 km)."
And use a proper tool when gapping, do not tap the plug on a flat surface to lower the gap. I gapped mine after watching this video from APR posted in 2015:
After I followed the above, zero misfires or EPC light, all excellent. I'm not saying this will solve your problem, just sharing how this solved mine.
Regarding your PCV, when it is bad to a point to cause misfires, it is usually also making noises, rough idle, leaking oil and showing other codes. And your car is still "young" for a PCV issue. I don't think it is your PCV causing misfires.
Did you change your coils?