Hey guys, I am still brand new to the s2000 club, having only bought my AP1 a few weeks ago. I have fallen in love with this car, but the engine light just came on for codes p0170 and p0172. I just received all of the paper work from the owner who owned it for over 11 years and just saw that he has had a recurring CEL having to do with fuel regulation. he went through a catalytic converter and clutch at 40k miles (right now it has 80k) and has had numerous things done to the fuel system to clear the lights. I am worried that this is going to keep happening to me, and I am a college student that's been saving up for this car, and I was breaking the piggy bank buying it for $13,000. I can't afford to dump money into this thing to keep it alive. Should I sell it and try again? Or just keep it and try and fix the problem? I don't know how severe AP1's problem with fuel regulation is but the previous guy spent about $6000 just for the CEL issue that kept popping up, along with another set of thousands fixing other various parts. I am bummed, and at a loss. Any advice is appreciated here

 

If there was upwards of 9k spent on this car in repairs I don't even see how that is possible.. A whole new engine could be had significantly cheaper than that? Something isn't adding up.

 

Why would a new engine necessarily fix a fuel systems or emissions issue? A whole new radio head unit is cheaper than buying a timing chain, for example.

OP, do you know what exactly the old owner did to try and fix this?

 

Those codes indicate that the ECU thinks the engine is running too rich...and is unable to correct the issue.

If the ECU detects a rich conditon, it will lean out the fuel mix. If after attempting to lean out the fuel mix, it still detects a rich condition, it will set a CEL.

This could happen if either the ECU is being given a faulty "rich" reading from the O2 sensor. Or it could be some output component failure like a leaky injector or torn FPR diaphragm.

Or the ECU is faulty.

Check the condition of the spark plugs. Do they indicate a rich condition? If so...maybe it actually is running rich. If they indicate a lean condition, the ECU is getting bogus information from some sensor.

Check your MAP sensor. Is the port clogged? Is the connector loose?

If after doing a few initial checks, you still don't know the issue...you need to take it to a shop that fixes emissions related issues. They'll need to diagnose the car with an oscilloscope.

 

Hey Man. Welcome to the forum. Sorry I can't help you but you will find this forum to be an endless resource for the issues your AP1 might suffer. Don't get frustrated, you'll figure this out.

 

He replaced the plugs twice, the coils once. I think he replaced the fuel regulator, pcv valve a couple times. I don't have the paper work with me but this was more of the cheaper stuff. I think he may have taken it to the dealer which would be racked up prices, but over the 11 year span that's how much he paid - wasn't all in one day.

I appreciate the feedback guys. I'll check the plugs and MAP sensor, could it be an O2 sensor? I tampered with the stock intake box to hear a little more grunt, and right after the code broke out, so I'm gonna put it back to normal to see if that helps. Could the MAF be related to this problem perhaps?

 

Yeah, pull plugs and post photos. Go from there...

Good luck!

 

S2000s don't have a MAF.

 

So I set the stock airbox back to normal and reset the ECU, and now the CEL (p0172) hasn't come back after over 100 miles. Does anyone else run into this problem? I was about to pull the trigger on a FIPK a week ago and I'm assuming this would throw the code back up there since the fuel/air ratio would be off again. Has anybody dealt with this issue?

 

To bump an old problem, I've cleaned out the MAP and IACV as well as the throttle body for good measure. It runs like butter at idle now, but the same engine code came back (P0172). Only thing is that the light comes on for a while (100 miles or so) and then will turn off, and when its off my car runs like new. After a few miles of good running, it comes back on again and acceleration tends to be pretty hesitant. I've never heard of an engine light going on and off like it's in a cycle. Could this be valve issues?