Top positive review
Best decision, don't buy the cheap brown ones. You'd think I installer a Supercharger!
on February 28, 2017
I have to first post the very negative review I posted for the cheap brown unmarked COPs also sold on Amazon. Because the moment I installed these, my 08 F250 was back in the game and no codes and no misfires or lags!
Review or cheap china product:
I've changed plugs and COPs on multiple vehicles over the years, namely a 2005 Mustang GT, 2001 Expedition, and my current 2008 f250 5.4ltr, and plugs on my 2007 Jeep Grand Cherokee, a 1995 Chevy k3500, and a 2005 Buick LaCrosse, I also have a great $350 Bosch code reader.
Im a general contractor, I do mixed driving all the time, I often have some kind of payload or a cargo trailer. I purchased my 08 f250 5.4ltr in mid sept 2016, with 120k miles on IG. I knew that it was overdue for new plugs and COPs, and other things. In late October the engine threw codes, spark and cop problems. I purchased oem plugs from my local autozone and I desperately needed to save money at that time, and decided against purchasing COPs I knew would work 100% from the local guy's and purchased online. I was worried at the time this product had only 3 reviews, and the other product that are yellow had several hundred reviews, but they cost significantly more. I figure: it's just a work truck, not a performance build. I waited to do all the installation at once. The moment after I was done and cleared all codes and even disconnected the battery for 10 minutes to wipe the computer, I reconnected and turned the engine over and it took forever to get it going. It wasn't a battery issue, I had the dealer put in a new one.
My truck then acted like it was a manual and I didn't know how to drive and kept the clutch in too long, it stalled every time it had to accelerate. I would later learn I had to have the truck warmed up every morning similar to a disel otherwise when I pressed the gas it would roll, chok and and misfire for 5+ seconds before finally starting to accelerate like a 1989 geo metro losing gear. I couldn't merge into traffic safely anymore. When it idled I could hear it misfire and rock between below 500 RPMS and it's normal idel of about 750 RPMs. It routinely died if I didn't feather the gas petal if I was reversing upna hill, say from a convenience store sloped parking space. I could barely make it hit 20 MPh unloaded and not under tow when going up a hill of really any steepness. And the engine breaking built into the truck for when I did tow also was malfunctioning. My transmission would routinely over work itself to make up for the lack of power and constant misfire and seemingly bad timing of the engine, it would reve up to 5k but then stall until I feathered the gas pedal and allowed the engines actual speed to catch up. When the weather was below freezing all of these problems became even worse!
I had to deal with this for months due to money and work conflicts: the code reader told me the same error codes as before. It ran WORSE than with the original faulty COPS that I purchased it with. The electrical tests seemed fine. Finally I purchased the more downside higher performance yellow COP kit, and just installed it. On a 30 mile mixed driving test drive, with multiple stops stop lights and parking, up hills and down hills, high RPM and not, here's no issue. You would think I put in a supercharger. And no codes: what a dangerous, irresponsible waste of money these parts are. The white residue on two of these 4 month old COPs is from the constant misfires.