⚡ Keep your engine firing flawlessly—because every spark counts!
The Dorman 42109 Extended Spark Plug Non-Fouler is a universal-fit, corrosion-resistant component designed to protect spark plugs from fouling and damage. Made with durable materials and backed by over a century of automotive expertise, this 2-pack ensures easy installation and extended spark plug life, supported by ASE Blue Seal Certified technical assistance.
| Manufacturer | Dorman Products |
| Brand | Dorman |
| Item Weight | 3.84 ounces |
| Product Dimensions | 6.75 x 1.77 x 0.94 inches |
| Country of Origin | China |
| Item model number | 42109 |
| Exterior | Ready To Paint If Needed |
| Manufacturer Part Number | 42109 |
A**B
Perfect Fit & Great Quality!
I bought these Dorman 42109 Extended Spark Plug Non-Foulers to help keep my spark plugs cleaner, and they worked perfectly! The quality is solid, with durable metal construction that holds up well under heat and pressure. They fit universally as described and were easy to install.If you’re looking for a reliable solution to extend spark plug life and reduce fouling, these are a great choice. Highly recommend!
A**A
so glad these still exist even when you are doing it right
Besides the fact the delivery drive can't read and delivered my package to the wrong apartment and someone else's package to my apartment. Everything was fine after I located it. They complain about wages and yet still can't do their job right?Anyways, after properly replacing my Cat with a new manifold cat on my FJ, NTK upstream, and Denso downstream. I just about had it with this P0420 code. I cleaned my MAF and my engine is running perfectly fine. Everything done to textbook service yet my O2 sensor kept reading irradic on B1S2. Reason I had to replace it in the first place was a Coil pack blew out on my Bank 1 side and it caused unburned fuel to ruin my cat and sensors. So after all that enough is enough. Put a Extender on B1S2 and it has smoothed out a bit and should be good.What's messed up is the cat is working a Voltage rages are within .1-.9 thresholds but the problem is the frequency is too frequent which can trip the code and when a FJ cruiser has codes on it disables a bunch of driving features. And doing a one wheel peel in the rain while turning on AT tires gets annoying after awhile.The pending code which was storing almost immediately hasn't popped back up yet so I'm assuming it should be good. If it doesnt I'll have to shove some steel wool or something in the spacer to smooth it out more.
A**.
Great option
These are great and make sure your check engine light stays off. Easy to install and fit perfectly.
W**L
No more engine light!
Works great for catalytic code P420 engine light. No longer a worry for me!
K**B
Good buy
Well made and sturdy worked great
M**Y
As advertised. Used in special application.
Used these for O2 sensors that kept alarming in our Honda Element. Drilled out bases to 1/2 inch. They work but now get occasional slow -to -read alarm. Perfect fit.
T**M
Worked well!
Definitely a great product if you're looking for some extenders for your emissions control issues.
J**A
Works for catalytic codes
Got rid of my p0420 on my 05 4runner. Took 15 minutes to install. Worth the money 100%
Trustpilot
4 days ago
2 weeks ago
