Ott's Performance Engineering

Ott's Performance Engineering is an agent for JDS Porsche of Cambridge, UK, and is a source for JDSPorsche rebuilt MAF (928 MY 84-95), and LH  engine control computers, 928 MY '87 and later.

Cost for the standard MAF is US$350, SuperMAF is US$450. The SuperMAF is only used on engines making over about 400 rwhp.

MAF testing is US$35.00. If your MAF needs replaced, the testing charge is waived. 

Rebuildable MAFs must have the internal venturi assembly that holds the platinum wire undamaged, the flange and groove for the snap ring that holds the screen undamaged and the plastic cover over the electronics must be undamaged and the original seal intact.

Note: MAF screens are scarce and replacements must be custom sourced. They are not inexpensive. Therefore any MAF sent as a core must have both screens intact and not damaged as in severely bent or stretched or not usable for a rebuilt MAF. Also, both snap rings must be present. Missing or damaged MAF screens, or snap rings, will be assessed an additional $15 per item above the basic US$350 cost for a JDSPorsche rebuilt MAF. Please do not remove the black cover, there's nothing in there that is repairable without expert knowledge.  A surcharge of US$20 may be added if the black cover has been removed.


Send your MAF to me for testing and replacement if it is out of Bosch specs.

Rebuilt LH computers are US$495. LH testing is US$35.00. If your LH is failed and need replaced, the testing charge is waived.

Send your failed LH to me. I will extract your eeprom chip, insert it into the rebuilt LH, and return the LH to you with your original cover lid.

Ground shipping within the continental US and Canada is included with the listed price. Shipping cost for faster delivery will be an additional charge. Approximately $50 for overnight.

The MAF rebuilds have a 2 year warranty and LH rebuilds a 3 year warranty against failure in normal use. Does not include failure due to water or fire damage.

You can send me your failed MAF or LH with a personal check included for payment, or PayPal to my account "". I'll return your rebuilt MAF or LH the next day usually by USPS Priority mail.

Street address if shipping by USPS, UPS or FedEx is:

Ott's Performance Engineering
7050 E. Horizon Dr.
Cave Creek, AZ 85331


Telephone 541-980-4500

More information on JDSPorsche rebuilt MAF, LH, & EZ-K as well as the Sharktuner, LH and EZ-K tuning device, and the "Spanner" diagnostic tool can be found at this link. JDSPorsche

For Sharktuner information contact Jim Corenman. Email to