Hello,

I have had this on going problem with my 06 XKR.

Just so you guys get an Idea of the mods I made, don't know if that is why my car is being affected.

Eurotoys ported supercharger and pully
Custom 2 1/2 inch intake with K&K
Nameless Performance 200 cells (only 4k miles on them)
Mina gallery exhaust with x pipe.

The problem I have been having with my car is I keep getting codes saying "fuel trim system too rich" "Bank 2 too Rich" "Bank 1 too lean"

One week my car is running to lean and the next week my car is running too rich???

I did some research and everything was pointing to the o2 sensors and MAF sensor.

So I changed them, put brand new ones in upper and lowers on both cats and a brand new maf sensor on.
The car is still running the same, super sluggish. I press the gas all the way and it takes the car 10 seconds to react to the peddle..

The worst problem I have now is that at 5k rpm my car rev limits automatically. Guessing this is called "pinking"?

I have no idea what else I can do to fix this problem?
Spark plugs? fuel pump?

Any help or suggestions are greatly appreciated!

-Alex

 

Do you have a way to check the fuel pressure? Unfortunately the later cars don't have the schrader valve on the fuel rail for an analog gauge so you'll need an OBD reader that can query the sensor.

Another thought is to check the manifold pressure reference tube that runs from the base of the S/C outlet to the fuel pressure regulator. It is on the right hand side between the S/C outlet and the charge cooler.

If this is pulled off then idle fuel trims will be way high because of a vacuum leak and the high boost fuel pressure will be too low because the regulator has no idea the manifold pressure is higher.

 

You need a tune. ecu doesn't know what's going on outside what it knows.

 

On some vehicles that may be true, on the XKR, the ECU can adapt to the mods that MiamiXKR made.

 

The stock ECU is pretty adaptable and can accommodate some radical changes (see Avos with his twin screw, reground cams, etc, etc).

Since you just replaced all those parts I would be suspicious of a vacuum/boost leak somewhere due to a bad seal.

When replacing the S/C there are a number of things that have to come apart, the outlet, the charge coolers, the bypass valve, the throttle body. All of these have seals and if any of them were left out or got smashed you could see those sort of problems.

If you have a reader that can show the fuel trims, it shouldn't be too hard to rule out. Or there is the old fashioned smoke test.

 

Is there anyway this problem can be from bad sparkplugs?

 

It's possible. Contrary to what intuition might say, a non-firing plug will result in a perceived lean condition and increase in fuel trims because the O2 sensor is measuring oxygen, not fuel, and when you don't burn it at all there is a lot of oxygen.

Do you see any indication of a misfire?

 

Yes I have somewhat. When i am crusing under 40mph lightly on the gas I feel the car misfiring.

 

Have you ever replaced your EGR pipe? I had similar codes (both banks, sometimes rich/ sometimes lean) and symptoms like you suggested (which felt almost like a misfire) and some research pointed to a possible egr connection - when I took a stethoscope to the motor I could hear a leak in the back behind the TB under the windscreen. When I removed the EGR valve and pipe I found the EGR pipe is made from a fine gauge pressed steel, with a ribbed flexible elbow - which (obviously given the build of that pipe) had a break in it. I replaced the pipe, and the EGR valve while at it, and that fixed my bank 1/2 codes. Total time about 3 hours, slightly awkward because it was under the windscreen cowl (tight, some remove the TB but I got by without it), pipe, valve and gaskets were around about 2-3 hundred if I remember correctly.

 

Today I checked the EGR pipe and it is in good condition.

Noticed some blowby in the intake.

My mechanic tells me that my car is running lean, since we changed the sparkplugs today.

When I get the codes from the car the ECU says i am running to rich.

My mechanic claims that if I get a haltech ECU + tune that I will no longer have any problems ever with this type of things.

Any truth to that?

 

I assume your mechanic tells you you're running lean by reading the plugs. It doesn't seem right that the ECU is giving this contradictory info, though.

I would get yourself a wideband o2 with a readout monitor, fire the car up, and get exact readouts for idle, cold, and operating. (you can get the kit for ~200$). You don't even have to install the wideband permanently; you can put it in the end of your tailpipe and sell the system later. A competent dyno shop will also have a wideband to take this readout, and if you look you might even be able to find a shop with a jag compatible tuner to update your A/F maps, if that's really the issue.

By the way, did this start after the high flow cats were installed? If so, a spacer is sometimes used for the o2's connected to high flow cats, since without it the o2's sometimes get thrown off. You can either buy this as a "spacer", or pick up a "Spark plug non-fouler" at your local parts store for a few bucks, and give it a go.

Like this:
http://www.m3forum.net/m3forum/showt...=320247&page=5

 

I strongly agree with Charlie's earlier suggestion. The fuel pressure should be checked. It is electronically regulated on 2003 and later cars and if it is fluctutating erratically it can easily cause your symptoms.

As was stated, it can be read over the OBDII port.

 

A good mechanic will NOT tune a problem away, he’ll fix the problem.

I don’t have an answer for you what could be the cause, as it could be a long list. So you need to eliminate possibilities, and work down the list.

 

@pomosv this happened much longer after the high flows install.
Where can you buy this obdII kit?

 

Various OBD2 scanners are sold locally and online. The cheaper ones won't allow you to tap into the more advanced sensors like fuel pressure as whitexkr suggested, however. Maybe getting one locally would help, I also believe there is a list somewhere on the forum of compatible OBD2 scanners.

If you're talking about the o2 "kit", you can pick up the wideband sensor kit online such as ebay, I have an innovative LM-1:
Innovate Wideband afr LM 1 LM1 | eBay

 

Question,
Will doing a flash on the ECU maybe fix the issue?