evoredy

iTrader: (7)

Hello all. I was torn on whether to put this in Engine/Turbo/Drivetrain or just here.

I just wanted to post to the community my experience with OMNI 4bar's over the last 2 two years. I've purchased 2 of them and they both exhibited intermittent operation after about a year of daily driving. I drive everyday and have been in hot climates (southern region). The car (DSM) sees 30 PSI on occasion and at least 20PSI every day.

My Evo still has the factory old-style MAP sensor casing with a Freescale MPXH6400A implanted into it wired directly with no filtering or decoupling. It is still in my vehicle 6+ years and counting.

The MPXH6400A is indeed an awesome sensor and I'm glad OMNI uses it (not sure if there are knockoffs, but they do not use a knock off).

To the point:

If you have intermittent issues or the sensor is just dead, your filtering capacitors and/or resistor have most probably failed. From everyone I've seen that posted issues, they are great with returns and hopefully they're tracking the issue/possibly small lot related. Definitely contact them.

IF you want to fix it/test it, gently open up the sensor (280ish degree heat for about 10 minutes/pry/if no movement/reheat or just accidentally break the casing like I did )

You will have to heat the sensor again to gently chisel the potting away around the C1, C2, and R1. Clip the capacitors and resistor, test, re-pot, and re-seal. You can add the filtering caps and resistors as per the Freescale MPXH6400A data sheet externally (on the harness) with higher tolerance components if you wish. It will work straight away as long as the MPXH6400A itself and circuit board are not damaged (unlikely). They were in immaculate condition as I checked every trace with a DMM. You will have to JB Weld the casing. It will hold just fine.

Upon my inspection, C2 and R1 were culprit as light pressure over the potting (which was 100% intact) would cause major fluctuation via logging. I believe they are the output filter circuit. IMO, my vehicles have noticeably better response without the filtering. My failure mode pulled the 5V output directly to ground as the cap and resistor seemed to short with physical pressure (boost/transient response/etc.). I went ahead and removed the input decoupling capacitor also.

Just FYI because I noticed some people wanted an answer!

tephra

iTrader: (6)

wow. going above and beyond dude

my 4bar shat itself (https://www.boostedforums.net/showth...ni4bar-failure) and i just put the stocker back in. but i wouldn't mind fixing mine up...

i wonder why, if its a physical problem, omni dont fix it..

planned obsolescence?

evoredy

iTrader: (7)

That's what I do when my vehicle cuts out dangerously and there is a wait time for a new component.

I think beefier components (other than map sensor) are in order. Might be a profit/vendor/lot issue thing which every company faces or does.

I really hope it's not planned obsolescence but many companies may do that nowadays.

mrfred

iTrader: (50)

I know of one shop that has reported to Omni that their MAP sensor reliability is not great. Hopefully they will fix it.

Can you post a drawing or high res photo showing what you changed to improve the MAP sensor responsiveness?

Klaiceps

iTrader: (18)

Thanks for sharing. I had an Omni 4 bar crap out on me. Super inconvenient. However at least Omni is good at sending out replacements. I sure hope they fix this reliability issue with their MAP sensors.

LetsGetThisDone

iTrader: (1)

I've had mine for 2 years, no problems, knock on wood...lol. Would hate to have a map ensor fail and leave me stranded since I'm on SD. Makes me think of getting a spare and keeping it in the car.

mrfred

iTrader: (50)

That's what I'll be doing.

Klaiceps

iTrader: (18)

A little update to this thread. A couple months ago I helped out a friend who is on SD and using an Omni 4 bar MAP sensor. Engine would shut off when he drove after warming up his car in the morning going to work and afternoon leaving work. It finally left him stranded not far from his house which prompted him to ask for some help. After doing some logging and trying everything in the book to get the car started, it was determined the MAP sensor was at fault. We swapped it out for a new Omni sensor and the car started right up. Fast forward 2 months later and that replacement sensor gave out. 2 months!! He swapped in a new one but now it's a question of not if but when will that sensor fail again. He's really bugged out at the moment because he doesn't want to be left stranded in a precarious situation. At this point, I'm going to give the AEM MAP sensors a shot since they seem to be more robust looking than the Omni sensors.

kaj

iTrader: (60)

Has this been exclusive to the 4 BAR? Because my car drives like crap at low RPM and idle.

**edit: I have a 3BAR. Just curious.

Klaiceps

iTrader: (18)

So far yes. I haven't tried another MAP sensor since I'm unaware of another 4 bar MAP sensor that has the correct settings to work with the stock ECU.

Klaiceps

iTrader: (18)

Just got an email from Bob at Omni Power and it seems they have an updated version of their 4 bar MAP sensor with new capacitors.

I'm hoping this will solve the issue with these sensors. Only time will tell.

On a side note, communication and service with Omni is great. Not once have they told me to go pound sand unlike some other "reputable" manufacturers/shops on this forum that supposedly have warranties on their products/services.

ExViTermini

iTrader: (25)

I had this issue while doing DE days at the track, it cost me a whole days worth of sessions

littlewack

I own two evos, both with OMNI 4-bars.

First one lasted for over a year, then died on me. OMNI replaced it no questions asked. The replacement has been working fine for 3 years or so


On my second car I got one DOA, OMNI replaced that one no questions asked and apologized, they let me know they had a bad batch from production that made its way out to distributors, they said (If i remember correctly) the electrical pins were the incorrect size (too small) so they didn't make a solid connection. They said you could bend the pins to make them contact in the harness better, but they replaced it no questions.

Replacement has been running fine for over 6 months now.

Even though I've had a bad experience with a few sensors. Customer service has kept me as a customer!! I love someone who stands behind their product. And I can understand things break sometimes, manufacturing doesn't go to plan. etc. etc.