My car's always been throwing a CEL ever since I put my RRM turbo kit (stage 2) on. I figured that it was from my header and/or test pipe, but never had it read because I heard that a lot of turbos cause a CEL and that it was no big deal. But I recently bought a scan tool and found out that the code is fuel trim too rich at idle (bank one). I need to pass emissions here in good old PA and I won't be able too if I'm throwing a code. I got by emissions last year because a guy hooked me up. He got busted since then so now I have to actually get it tested. The good news is that that's the only code I'm throwing. I've done some research and I've read that the RRM kit does run a little rich. Has anyone else had similar issues? What could I do to fix this? The car runs fine, it just runs a little rich at idle. I've always known this but didn't think it was what was causing my CEL. I just replaced the 1st O2 sensor the beginning of this year, so I highly doubt that that's the problem (plus if the sensor was bad it would usually throw a code for that too). I saw that RRM now has the software to alter the piggyback's settings. Should I get the software and try to correct the fuel trim myself? Does the software work with older piggys, or just the newer ones(mine is an older piggy that came with the stage 2 turbo kit)? Any suggestions would be very helpful.

 

If its running rich at idle it has nothing to do with the kit per se. You have an air leak somewhere post MAF. Everything up to boost is taken care of by the stock ECU and o2 sensor, once you hit positive pressure is when the turbo kit components take control. I'd double check all hoses, vac lines, and double check the BOV recirculation port to make sure you arent leaking out any air at idle.

 

So the piggy, and bigger injectors don't really effect anything until I hit boost? I don't fully understand how the MAF does what it does when it comes to the RRM setup. The MAF is installed in the cold air intake pipe that's attached to the turbo's air inlet (so it never meters compressed air) and it resides near the bottom of the drivers side fender. The BOV recirc hole on the CAI pipe is located between the MAF and the turbo. So if the turbo is sucking in air, then how does the MAF meter the air that is recirced when the BOV goes off? Even if there was a leak in the BOV recirc port at idle, wouldn't the air travel through the recirc pipe and then be sucked into the turbo without being metered through the MAF? So how does the MAF know that there's a leak somewhere? I've always been confused by the MAF's location and how it works.

As far as vacuum lines I have checked those a few times and they all seem to be fine.

 

Well first off i'm an idiot and didnt read that you were stage two, so that creates another cause for the rich condition. either A) the piggy settings are too rich for idle (i'pm not sure how rrm sets the fuel curves for stage 2) or B) you are leaking air post MAF.

The MAF reads the air that is being sucked in by the turbo, once the air travels past the MAF the computer is recognizing that all of that air is in the piping and it should not be escaping anywhere. The BOV recircs to after the maf so the air that WAS in the pipes before the shift is still in the pipe. In a setup like RRM puts it where the MAF is first in line after the filter the BOV has to be recirculated. Think of it this way... the turbo spools up and sucks in X amount of air, the air passes through the filter and then through the MAF. The MAF reads X amount of air passed through so there is X amount of air in the charge pipes. Now if you were to vent to atmosphere and not recirculate then Y amount of air is being vented out during the shift. So now, during the shift, the MAF says X amount of air was in the pipe just before the shift, but during the shift Y amouunt of air was vented from those pipes, so now the computer is saying there should be X air in the pipe, but theres actually X minus the Y amount of air that was vented so the a/f ratio is thrown off. When you recirculate that air back into the intake after the maf then the MAF still reads X amount of air, and there actually still is X amount of air in the pipes.

So i think your problem either lies with A) an air leak, or B) piggy settings are too rich at idle (if indeed the RRM piggy leans out idle). I'd first do a boost leak test, and make sure everything post MAF is tight and no air is getting out. If you dont find any leaks, then i'd give RRM a call and see what they say.

 

I found a pretty nice boost leak tester at boostpro.net that I'm ordering today. Hopefully that will tell me if I have a leak. In the mean time, does anyone think the piggy could be running it too rich during idle? Can a really small air leak in the charge pipes or BOV cause the car to run that rich at idle?

 

Dumb question - why check for a boost leak at idle? Last I checked, you're not making much boost at idle...

Even dumber question - have you called RRM yet? You know they're the best source for troubleshooting their own kit. . . . . . .

 

Haha yeah i was just typing out that response about not being in boost as you put that up there.....dont bother with a boost leak tester. You are checking for major leaks like hoses not totally tightened, rips in couplers, etc

And yeah, call RRM if theres nothing visually missing or loose

 

Yeah but I can still check for small leaks by pressurizing the system with a boost leak tester. Even though my problem isn't during boost, I can more easily find small leaks by pressure testing. I'll probably call RRM sometime this week. But I'll be at the beach and I might wait till I get home before I call.

 

Just reading all you guys' threads makes me wonder about the problems that await me when I go from N/A to Stage 2. wow.. I was thinking of hopefully running stage 1 first, but since I have all the stuff for Stage 2, I'd thought on skipping it and just setting my max to 9psi.

 

This is the same problem I was running into when I tried to go stage 2. Granted, I was using 440 cc injectors whereas the RRM stage 2 kit comes with 370cc. I also had the v.1 piggyback and the software and I couldn't ever lean it out at idle. Adjusting the idle screw helped a little, but my idle was really rough and would die at times from too much fuel. I ended up just abandoning trying to go stage 2 for the time.

 

wow, so that's not good at all. Going stage 2 seems it'll cause alot of problems. So I'll just keep it at stage 1 at install and when i decide, i'll move into the upgrade.

 

That's what I'm doing

 

Is there any way that I can lean out the fuel without having the piggy software? The car runs fine, I just need it to stop throwing the damn CEL so I can pass emissions.

 

Go back to stock.

But seriously, no.

 

I was reading the RRM website and it doesn't look like I'll be able to lean out the fuel mixture during idle anyway because it's running in closed loop, and fuel mixtures can't be calibrated in closed loop. Or am I just not reading it right? Anyone have any experience with this? Well, I'm back home from the beach now and will be calling RRm today anway, but if you have any info that would help, I'd appreciate it.