I recently bought a 1999 mercury cougar. At first I was only attracted in a 5 speed manual car as all of my cars have been automatic and I like driving stick. Only a week later I chose to make it a machinate car. I am in the process of picking out a turbo kit, but I chose to start off simple in anticipation of the kit arrives. The car came with a fart can, but it contains the stock exhaust other wise. The car has absolutely no mods and is bone stock. I went out now and ripped off the fart can muffler, and I also removed the stock air intake box and am running it open at the mass air flow sensor. The check engine light came on not long after I started driving the car with this new set up. Obviously wit no muffler and no air intake, there is considerably more air entering the engine, and having less back pressure allows the engine to suck more air as well. Being a somewhat modern fuel injected car, I thought the ecu and o2 sensors would be able to exchange the a/f ratio but it is having a hard time adjusting to the new set up. I check the codes, and pulled a p1131 and a p0136. The p0136 was that the 02 sensor on bank 1 was running at to low of a voltage for to long of a time, which indicates the the engine is running lean. The p1131 is pretty much the same thing, running lean. I also noticed while accelerating from 80-120mph that it studdard and struggled to accelerate every once in a while. I drove the car about 60 miles after notch it up and allowing the engine to breath a small bit, and I don’t reflect the car has adjusted to the new set up yet. My question is will allowing the car to run and drive for a while allow the car to exchange to the new set up, or what else do i need to do. I have read about reflashing my ecu or installing engine management software, but I dont know where to start for that, and would this new set up really require that. Its such a insignificant adjustment in my opinion, with no boost installed yet. Obviously when I install the turbo kit, I will be upgrading the pump, injectors, and ecu any how to keep up with the increased are flow, but should I really need these things already with an opened up intake and no muffler. If so, what would be the best engine management to work with to help increase the fuel, and to right the a/f ratio. Any help would be appreciated. And dont try to tell me it doesn’t increase horse power, because it does, possibly only 2-3 at best.

Best answer:

Answer by bandit_60
sounds like your making the valves too cold. you need a certain amount of back pressure before it can run right.

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