Hello guys, i've got an 88 dpfi d15b2 civic hatch and is driving me crazy. The thing is; the car runs great until i get into the highway, then the check engine light comes on and it starts running like crap. It has like poor reaction to the throttle. This only happends when i'm at cruising speed or when i floor it till like 5k rpm. The strange thing of all is that the CEL throws code 1 only, oxigen sensor. i've already replace the o2 for a brand new ntk one month ago and clear the codes. Also i replace the TPS because when i bought it it had code 7 and was nearly undriveable. Now it only throws code 1 and starts running like crap, really weird. Could it be the fuel pressure regulator? i'm out of clues, please help

 

Check for continuity in the wire from the O2 sensor plug to the ECU.

 

continuity is ok, i've check it when i install de sensor. the weird thing is that it shouldn't run like crap if the o2 was bad. it has nothing to do with it, that's why i wonder if the fuel pressure regulator could be bad. it seems to me that the problem is fuel delivery at high rpm. it's really strange. anyone know how to test de FPR to see if it's bad?

 

The O2 sensor has alot to do with how it runs. If it thinks it is running lean, but it's not, it will richen the mixture and cause the car to bog and stumble. The same thing happens if you have an adjustable FPR and set it too high.

 

Only thing comes to mind immediately is, you said you replaced tps, did you make sure its dpfi tps? I don't know how it would react to the mpfi being that it turns reverse but just a thought since the dpfi tips is hard to find and cost $100+ when you do find it.

 

yes, it's a dpfi tps. i'll be changing the fuel pressure regulator, hoping thats the issue. i can't think of anything else. if a brand new FPR doesen't fix the CEL, my ed6 will be up to sale in no time. i'm simply done with this old piece of s***

 

code 1 also refers to "oxygen content" so if the sensor is good and your certain the circuit is good, less than 0.5 ohms contiunity, you dont test the FPR itself, but rather check the system pressure with a gauge, quick check on the plugs can tell you whats going on in the chambers, whethers its rich or lean

 

thank you very much for your help my dude, i really appreciate it. i'm from Argentina and over here the car market sucks. people love french manufacturers like peugeot and citroen, extremely shitty vehicles. over here no one knows nothing about hondas, especially old *** ones, so i'm depending 100% on the information i get from this forum. it is, without a doubt, one of the best honda forums of the hole internet