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Tech info on MP - DPF & EGR

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Tuning Technical Information

We are increasingly getting inquiries from customers having problems with standard vehicles. They are being frustrated with New Car Dealers who are not listening to their complaints about their vehicles poor Economy or Performance. Dealers are finding themselves caught in the middle as manufacturers dumb down the test procedures which the dealers are only allowed to carry out. They are only permitted to replace what their Diagnostic Equipment determines, so faulty sensors sending incorrectly calibrated signals, result in the Diagnostic Equipment not seeing the real faults. These Pages are here to give you a better understanding of how your vehicle works & help you diagnose problems you are having with your vehicle.

DPF - Exhaust

Although we can see benefits in modifying Active DPF (Diesel Particulate Filter) systems like the type used on the NS Pajero etc.. & there are benefits in reducing restrictions in exhaust design. There is no reason to delete passive style DPF’s fitted to other cars.
As an example, one of our young customers asked our company to do a full Rally style tune to his Hot Hatch CRD. This vehicle achieved a huge power gain. We were also able to prove that the increased Exhaust Temp was improving the DPF’s ability to burn off soot particles, despite the fact that this vehicle did short runs in city conditions & already had a sports exhaust after the DPF. Previously in standard tune the vehicle had to have the DPF cleaned by the dealer every 6 months. After tuning, the vehicle ran for 11 months without needing cleaning. But it was this point the customer made the mistake reading on forums that deleting the DPF will increase power. He had the DPF cut out & replaced with tube. There was no power gain, & now his vehicle had exhaust smoke problems which were previously being absorbed by the DPF. We had to de-tune the Rally program, customer was unhappy that he could not run same power as before. He then fitted a Sports DPF, which although being Hi-flow, was still much smaller than standard. We could still not use the full previous Rally Program, so power was still less than before. To avoid the excessive cost from the Aust dealer, he purchased a new original style DPF from Europe. Finally after thousands of dollars spent, we then were able to re-install the full Rally style program.
The biggest problem for DPF’s is short running, city style driving. They need to build up temperature to function so they can burn off the soot particle deposits. You need to give the vehicle a drive at freeway speeds, at least 15-30 minutes per week, especially for a standard, un-tuned engine.
From Wheels Magazine May 2010 page 137 - Long term test vehicle: Audi A6 Allroad 3.0L V6 TDI at 5498km - A three-stage warning light system warns Audi diesel drivers their car’s particulate filter is becoming blocked. If detected at stage one, a brisk 15-minute freeway run clears the filter and negates the need for service. Diesel legs need stretching: With so much torque on tap from just 1500rpm, the driving experience is relaxed and effortless. Or at least it was, until one of the little-known quirks of the modern turbo-diesel came to light in the form of a drop in power and a combo of warning lights. A visit to the dealership diagnosed a blocked particulate filter and a regeneration program quickly returned the Allroad to full power.

From Wheels Magazine July 2010 page 169 - Long term test vehicle: Jaguar XF 3.0D V6 TDI at 4902km Inner West drinker - The two weeks of inner West Sydney driving that provoked the DPF warning light also played havoc with the Jag’s fuel consumption. Instead of the mid-6s produced on interstate journeys, the XF plunged to a worst of 14.3L/100km. Particle Theory - Warning message prompts big burnout. With just under 4200kms on the odometer, the XF’s on-board computer triggered an ominous message on the dash monitor: “DPF FULL – see handbook”. A thorough reading revealed that the DPF had not been reaching the required temperature (around 600degC) to allow the automatic burning off of the accumulated carbon diesel particulates. In other words soot. Too much short-trip, stop-start driving, apparently. If the message appeared on a red background, I needed to immediately return the car to the dealer. If amber, by driving at a steady 75-120km/h for up to an hour, I could clean out the filter. And it was amber, sure enough, after 25minutes at a constant 100km/h the warning light disappeared. Phew. The handbook suggests failure to act could result in expensive damage to engine and emissions system.

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EGR Valve

The EGR (Exhaust Gas Re-burn/Reheat) Valve opens every time you take your foot off the accel pedal. They frequently block up or fail & should never have been fitted to Diesel engines. Releasing hot exhaust gases & large soot particles back into the inlet manifold can never be sustained. No vehicle manufacturer has informed any car dealer that this system can only work if it is maintained. Car dealers will only fix it when it breaks.
Early model cars can remove or block the system, & on engines like the Nissan ZD30 this can greatly prolong the engine life. On this engine the EGR port lines up with the inlet port of number 3 cylinder. Blasting hot exhaust gases & soot particles into the combustion chamber. These particles form heavy deposits on top of the piston & keep extending the top of the piston until there is no compression area left, then the piston strikes the cylinder head & the piston breaks.
Late models can not block the EGR off because they use the MAF to tell if it is blocked & log a fault code or have reduced performance. Some people install a blanking plate, but have to drill a hole just large enough to not cause a fault code. This reduces the amount of heat & particles, but as soon as the hole blocks up, the fault code comes back & it needs to be cleaned again. Mitsubishi replaced entire inlet manifolds on their 3.2L CRD engines, due the EGR deposits blocking the MAP Sensor & number 3 cylinder ports. Nissan Patrol 3.0L CRD EGR valve opens for too long a duration, causing the inlet manifold to overheat & warp. MorePower does have a simple solution for some vehicles.

MorePower EGR Delete

Delete EGR (Exhaust Gas Reheat/Recirculate) Valve function electronically by simply adding another resistor to the factory resistor - The Temperature Sensor on Air Flow Sensor is just a Resistor being cooled by the air flow. This simple process of cutting one wire & adding an extra Resistor tells the ECU to not activate the EGR.

Japanese car makes were facing their own Dieselgate scandal last year when the Japanese Govt tested their Diesel models & found they emitted many times higher than their claimed pollution levels. Toyota blamed the cold weather caused the vehicle emission controls to switch off as quoted: Toyota “will continue to make improvements to reduce NOx emissions during on-road vehicle operation,” a company spokesman told the Wall Street Journal, with Nissan and Mitsubishi giving similar answers. It is believed cold weather may have affected the tests, with engines potentially switching off exhaust recirculation systems (EGR) as a protection measure. Diesel sales make up just 4% of the Japanese market.

This process of fitting an additional Resistor only switches off the EGR & does not interfere with other engine functions. The engine mixtures are calculated by an Air Temperature Sensor located near the Inlet Manifold. This Manifold Temperature Sensor reads the actual Air Temperature after it has been compressed by Turbo & Cooled by Intercooler.

Just let us know which vehicle you have then we can supply you the correct value Resistor & instructions on how to fit it for:

Audi 2.0L CRD (Please Supply Photo of Sensor)

Citroen 4cyl hdi (4 & 6 wire sensors)

Citroen V6 hdi (2 Resistors are required to order)

Ford Ranger 2.5-3.0L

Ford Ranger 2.2-3.2L

Ford Territory 2.7L

Holden Rodeo CRD/Colorado 3.0L

Holden Colorado 2.8L

Isuzu Dmax Mux 3.0L

Jeep 2.8L

Jeep 3.0L (Merc OM642)

Landrover/Range Rover 2.7L

Landrover/Range Rover 3.0L V6 & 3.6L V8 (2 Resistors are required to order)

Mazda BT50 2.5-3.0L

Mazda BT50 2.2-3.2L

Mitsubishi Challenger, Pajero & Triton 2.5-3.2L CRD

Nissan Pathfinder & Navara 2.5L CRD (Excl D22)

Nissan Pathfinder & Navara 3.0L 550 V6

Nissan Patrol 3.0L CRD

Peugeot 4cyl hdi (4 & 6 wire sensors)

Peugeot V6 hdi (2 Resistors are required to order)

Toyota Hiace, Hilux & Prado 2.5-3.0L D4D (models up to mid 2016)

Toyota 4.5L V8 D4D (models up to mid 2016)

VW 1.9-2.0L (Please Supply Photo of Sensor)

Most EGR Blanking plates are being fitted in wrong position, they should be fitted at exhaust manifold, but this is hard to do& the overheated bolts are likely to break.

Then the Blanking plate causes Check Engine fault light, so they drill a hole in Blanking Plate - But this then is not really a Blanking Plate any more - It Has A Hole In It!

When hole carbons up with soot - Check Engine Light is On again. Blanking Plate needs to be removed & cleaned - over & over again!

No Blanking Plate Required if EGR does not Open during normal driving.

We are now working from the opposite direction from when we first started years ago. At that time, the workshops we supply were fitting blanking plates, now they fit Resistors instead.

Fitting a blanking plate & then having to drill holes to stop fault lights, then having to clean the hole or drill it larger so it took longer to carbon up. But then the EGR Exhaust Port would also carbon up as well so even drilling a hole no longer worked & the whole system had to be dismantled to fix the blockage near the exhaust manifold.
We found by adding a Resistor we could avoid drilling the hole & avoid pulling the whole system apart. Now we fit Resistor instead & eventually the EGR Exhaust Port blocks up close to the exhaust manifold, a long way from the inlet manifold. Once the other end is blocked with soot (which will happen anyway) there is nothing getting through & with Resistor fitted - no EGR Fault Light.
With the Resistor fitted the EGR function is still part of the vehicles Systems Check. This also happens if you do an ECU reprogram to delete EGR (at a cost of up to $1200) – the vehicle still carries out a Systems Check, which makes sure the components work. Vehicles also do System Checks of Airbags & Anti-lock braking systems etc... it does not mean the vehicle has to activate the systems, just check they are not faulty.

The Resistor approach sounds complicated & overall it has taken years of development & testing to get to this point of just using a single resistor. We previously made full Emulators which were much more complicated & would not be possible to self-install.

Vehicles with worn/old/dirty MAF (Air Flow) Sensors & operating in hot climate conditions can sometimes require to fit 2 Resistors in line to compensate for their condition. Prior to fitting the Resistor, the MAF Sensors at this stage are activating EGR more frequently due to the wear/calibration problems. This is only due to the calibration of the sensor being further out from standard. It is best to try fitting one Resistor first, the value of the Resistors we have chosen for the vehicles has been tested to work in most conditions.

Vehicles with twin MAF (Air Flow) Sensors also need to fit 2 Resistors.

Process can be reversed at any time by simply removing the resistor & re-soldering the 2 wires.

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Find out more about:

Fuel Pressure Myth

Why does the Dyno graph show all the power gain at only high RPM?

Throttle Position Sensor & Accelerator Pedal Position Sensor

Fuel Delivery systems

MAP & MAF Sensors

VNT - Turbo Control

VSV - Variable Swirl Valve

Technical info on Morepower Tuning

Morepower Tuning Overview