I just recently bought a 99 civic it was running good but recently the mph gauge has been going crazy and when I drive it feels like it wants to brake it self it gets slower even when im pressing the gas then speeds up again but keeps repeating it self idk what it is and need help pleasee

 

Bone stock 99 Civic? What trim?

Post the CEL codes.

 

Yea its bone stock besides a intake. Its a single cam DX model if that helps?

 

CEL codes?

 

Oh yea thats another thing my buddy tried scanning it and the computer didnt turn on but it did on his so I dont know how to fix that either

 

Does the CEL work? If so, jump the service connector to pull the codes.

https://honda-tech.com/honda-civic-d...lists-1901557/

 

For the code reader problem, check whether hood fuse 43 is blown.

 

Ok so instead.of he check engine light the srs.was blinking??? And it blinks 10 times and then pauses for 2 seconds and then 1 quick one

 

And yea 43 was blown

 

That's an airbag system problem.

Code reader should power up now.

 

Thanks it worked and it gave me this..
025
Cat
Htr
Eva
And it said no dtcs are stored in the vehicle..?

 

Thanks it worked and it gave me this..
025
Cat
Htr
Eva*
And it said no dtcs are stored in the vehicle..?

 

Try taking off the air intake filter and take it for a ride to see if there is any difference. Some times a cheap air intake filter will slip down too far on the intake pipe and cause a air flow restriction. Your car performance problems sound like it could be a air flow restriction problem.

 

OP, is your CEL on? Does it work? It should come on for ~2 seconds when you turn the key to ON(II), then turn off. Your SRS light is another issue that you should address, but isn't related to your described issues. What ECU does your car have? You can find the ECU behind the passenger kick panel. There will be a sticker on it with a series of letters and numbers. In that series, there should be P2E, but given that you just bought the car, we shouldn't assume anything. It might be P2P, or P28. If it's anything other than P2E, you have an issue there. When was the last full tune up? Have you checked ignition timing?

 

OP's issue is fluctuating, not constant. An intake restriction, like a collapsed filter, would first off be constant, and second off not noticeable until the engine was eating the filter.

 

Let's do a reset. I cleaned up some off topic remarks. From this point forward, please make comments to the OP rather than to each other. Thanks.

 

Just found out one of the sensors from the tranny were loose causing all these problems to happen haha thanks for ur.time tho(:

 

A sensor from the tranny was loose it wasnt cliped on right causing all these problems to happen. So I clipped it.on right andbits working perfect again.thanks tho man I learned new things from u (: appreciate it